This is a realistic expectation, as the teams will need to learn new skills, collaborate more effectively, and adapt to changing requirements. However, the benefit of feature teams is that they can deliver working software that provides value to the customers and stakeholders every Sprint, rather than waiting for the integration of different components.
This is a natural consequence of changing the team structure and culture, as the teams will need to overcome some challenges and conflicts, build trust and rapport, and establish a shared vision and goal. The Scrum Master can help the teams with this transition by facilitating communication, coaching, and mentoring.

In complex domains, you are only able to know the outcomes in hindsight. Empiricism, from which Scrum was founded on, asserts that knowledge comes from experience and making decisions based on what is known. New knowledge will emerge as work is being done.

Explanation
As the Scrum Master, your role is to serve the Scrum Team by helping them to work effectively and deliver value. You are not responsible for managing the work or assigning tasks to the Developers. You should respect the self-organization and autonomy of the Developers, and support them in finding their own solutions to the problem. You should also facilitate collaboration and communication among the Developers and with other stakeholders.
Some reasons why option B is the correct answer are:
Asking the Developers what value they get by having the Daily Scrum with all team members present and what might go wrong if all Developers do not attend. This action will help the Scrum Team to understand the purpose and benefits of the Daily Scrum, and to identify and address the risks and consequences of missing it. The Daily Scrum is a 15-minute event for the Developers of the Scrum Team to inspect progress toward the Sprint Goal and adapt the Sprint Backlog as necessary, adjusting the upcoming planned work12. The Daily Scrum also provides an opportunity for the Developers to identify and communicate any impediments that are hindering their progress, and request help from the Scrum Master or other team members to resolve them12. The Daily Scrum improves communications, identifies impediments, promotes quick decision-making, and consequently eliminates the need for other meetings12. The Daily Scrum is not a status meeting, but a way for the Developers to collaborate and self-organize around the most important work for the next 24 hours12. If a Developer is missing the Daily Scrum, they may miss important information, feedback, or support from their peers, or they may cause delays, confusion, or conflicts for their team. The Scrum Master should encourage the Developers to share their perspectives and experiences on how the Daily Scrum helps them achieve their Sprint Goal and create a valuable Increment.
The Scrum Master should also help the Developers to come up with their own solutions on how to ensure full attendance and participation in the Daily Scrum. The Scrum Master should not impose or dictate a solution, but rather coach and guide the Developers to find what works best for them. The Scrum Master should also help the Developers to agree on some ground rules or norms for their Daily Scrum, such as when, where, and how to conduct it, what topics to discuss, and how to handle any issues or conflicts that may arise.
Some reasons why the other options are not correct are:
A: You do not intervene. The Developers own the Daily Scrum, so they should deal with any issues with attendance. This option is not correct because it violates the Scrum Master role. The Scrum Master is accountable for establishing Scrum as defined in the Scrum Guide1, causing change that increases the productivity of the Scrum Team1, and working with other Scrum Masters to increase the effectiveness of the application of Scrum in the organization1. The Scrum Master should not ignore or avoid a problem that affects the performance or well-being of the Scrum Team, but rather help them address it in a constructive and respectful way. The Scrum Master should also not assume that the Developers know how to deal with any issues with attendance, but rather teach them how to do so effectively.
C: Talk to the Developer who is missing the Daily Scrum and ask her to always attend the Daily Scrum.
This option is not correct because it violates the Scrum framework and the Scrum Master role. The Daily Scrum is an event for and by the Developers12, not for reporting or accountability to anyone else.
The Scrum Master should not interfere with or dictate how the Developers conduct their Daily Scrum, or make unilateral decisions on behalf of them. The Scrum Master should also not single out or confront a Developer who is missing the Daily Scrum, but rather involve all Developers in finding a solution that works for everyone.
D: Teach the Developers how to deal with this situation by attending the Daily Scrum yourself. This option is not correct because it violates the Scrum framework and the Scrum Master role. The Daily Scrum is an event for and by the Developers12, not for anyone else's inspection or intervention. The Scrum Master should not attend or participate in the Daily Scrum unless they are actively working on items in the Sprint Backlog12. The presence of an outsider may disrupt or influence the dynamics of the Developers' communication and collaboration. The Scrum Master should also not teach by doing, but rather by coaching and facilitating.
References:
What is a Daily Scrum? | Scrum.org
What Is a Daily Standup? | A Guide to Running Effective Standup Meetings | Atlassian

When multiple Scrum Teams work from the same Product Backlog, they need to collaborate and coordinate their work to deliver a potentially releasable Increment that meets the Definition of Done. This requires minimizing dependencies between Scrum Teams, such as technical, functional, or organizational dependencies. Dependencies can cause delays, rework, waste, and lower quality. Scrum Teams should strive to be cross-functional and autonomous, and use techniques such as feature slicing, dependency mapping, and integration testing to reduce dependencies.

Explanation/Reference: