Explanation
The next step for the business analyst to take before build can begin is to get approval and signoff on the requirements from stakeholders. This will ensure that there is alignment on what needs to be done, how it will be done, why it will be done, who will do it, when it will be done, etc. Getting approval and signoff on requirements is also important for managing scope changes or expectations later in the project lifecycle.
Defining the minimal viable product is a step that is more relevant for agile methodology than waterfall methodology. Scheduling sprint planning meetings is also a step that is more relevant for agile methodology than waterfall methodology. References:
https://trailhead.salesforce.com/content/learn/modules/salesforce-business-analyst-certification-prep/requirement

The Salesforce App cannot be found in the AppExchange market. The AppExchange is a marketplace for Salesforce apps, components, and consulting services, but it does not host the official Salesforce app itself.
The Salesforce App can be found in Google Play and App Store markets for Android and iOS devices respectively. References: https://help.salesforce.com/s/articleView?id=sf.appexchange_overview.htm&type=5

The best practice for handling an urgent, high-priority change request in Scrum is to add it to the prioritized backlog for the next sprint. This way, the change request can be reviewed by the product owner and estimated by the development team before being added to a sprint. Adding a change request to an ongoing sprint would disrupt the planned scope and schedule of work.
References:
* https://trailhead.salesforce.com/en/content/learn/modules/salesforce-business-analyst-certification-prep/ma
* https://www.scrum.org/resources/blog/how-handle-change-request-scrum

Explanation
When a business analyst learns that another team also needs email integration in the near future, they should include that team during discovery. This is because including all relevant stakeholders early in the project can help to identify common needs, avoid duplication of work, leverage synergies, and deliver value faster. The business analyst should invite the operations team to participate in discovery activities such as interviews, surveys, workshops, observations, etc., and capture their requirements, expectations, and feedback. The business analyst should also communicate the project scope, timeline, and risks to both teams and manage any changes or issues that may arise. References:
https://trailhead.salesforce.com/content/learn/modules/salesforce-business-analyst-certification-prep/customer-di