Explanation
A functional requirement specification is a statement that describes what a product or service must do or provide to meet user needs or business objectives. It should be clear, concise, testable, and measurable. The option B is an example of a functional requirement specification because it describes what the portal should do (allow for partners to upload monthly sales reports) without specifying how it should do it or why it should do it.
References:https://trailhead.salesforce.com/content/learn/modules/salesforce-business-analyst-certification-prep/

This answer states that reviewing the services team's goals, initiatives, strategies, and obstacles is what the BA should do to determine if the current solution of implementing an Experience Site that allows customers to view Knowledge articles and submit cases is adding value to UC's business. Goals are what the services team wants to achieve or accomplish in terms of business outcomes or benefits. Initiatives are what the services team plans to do or implement to achieve their goals. Strategies are how the services team executes or delivers their initiatives. Obstacles are what prevents or hinders the services team from achieving their goals, implementing their initiatives, or executing their strategies. Reviewing the services team's goals, initiatives, strategies, and obstacles means that the BA analyzes and documents these elements related to implementing an Experience Site that allows customers to view Knowledge articles and submit cases. Reviewing the services team's goals, initiatives, strategies, and obstacles is what the BA should do to determine if the current solution is adding value to UC's business because it helps the BA to measure and evaluate the performance and impact of the current solution against these elements. References:
https://trailhead.salesforce.com/en/content/learn/modules/salesforce-business-analyst-quick-look/use-stakeholder

Explanation
The best practice for giving all team members access and visibility to the most recent user stories as the project is in motion is to define a common repository to hold all user stories and track changes over time. A common repository is a centralized location where all user stories are stored and managed. It allows all team members to access, view, edit, comment, prioritize, assign, and update user stories as needed. It also tracks changes over time and provides version control and history of user stories. A common repository can be a tool such as Jira, Trello, Asana, or Salesforce Agile Accelerator. References:
https://trailhead.salesforce.com/en/content/learn/modules/business-analysis-user-stories/manage-user-stories

The business analyst should do to gain the necessary buy-in and support from the sales team to ensure a solution meets the requirements is to ask questions to understand their needs and focus on shared goals.
Asking questions is an elicitation technique that allows the business analyst to gather information, clarify assumptions, or validate understanding from stakeholders. It can help the business analyst understand the sales team's doubts or concerns about the new tool, and address them with empathy or evidence. Focusing on shared goals is a collaboration technique that aligns stakeholders on a common vision or outcome for a project or initiative. It can help the business analyst show how the new tool will benefit the sales team and meet their expectations or needs. Presenting the pros and cons of the decision by using logic and facts may not be an effective way to gain buy-in and support from the sales team because it may not address their emotional or psychological barriers or resistance to change. Demonstrating expertise and clearly stating the decision is final may not be an effective way to gain buy-in and support from the sales team because it may not involve them in the decision-making process or respect their opinions or feedback. References:
https://trailhead.salesforce.com/content/learn/modules/salesforce-business-analyst-certification-prep/customer-di
https://trailhead.salesforce.com/content/learn/modules/salesforce-business-analyst-certification-prep/collaboratio