The business analyst's role during UAT is to coordinate stakeholder participation and notify the team when scenarios fail so IT can solve potential problems prior to go live. The business analyst is responsible for facilitating UAT by ensuring that all stakeholders are involved and engaged in testing the solution according to their roles and responsibilities. The business analyst is also responsible for monitoring and reporting on UAT progress and results by tracking any issues or bugs that are detected during testing and communicating them to the IT team for resolution. The business analyst's role during UAT is to ensure that the solution meets the requirements and expectations of all stakeholders before it is deployed to production. References:
https://trailhead.salesforce.com/content/learn/modules/user-acceptance-testing-video/learn-about-user-acceptance

Explanation
The best practice for identifying which stage in the sales process the industry standard due-diligence should be embedded is to develop a process map as a base, work with stakeholders to understand the trigger point, and locate the stage. This practice helps to:
Develop a process map as a base: This provides a visual representation of the sales process, showing the steps, inputs, outputs, roles, and decisions involved in each stage.
Work with stakeholders to understand the trigger point: This helps to elicit feedback and insights from the stakeholders who are familiar with or affected by the sales process, and identify when or why the industry standard due-diligence is needed or required.
Locate the stage: This helps to determine where in the sales process the industry standard due-diligence should be embedded, based on the trigger point and the business logic. References:
https://trailhead.salesforce.com/en/content/learn/modules/business-analysis-process-mapping/create-a-proc

Explanation
The action that the business analyst should take to quickly introduce new functionality to impress the customer is to demo standard features and elicit feedback from the customer. Demoing standard features means showing the customer how Sales Cloud can provide out-of-the-box functionality that meets their needs or expectations without requiring extensive customization or development. Eliciting feedback means asking the customer for their opinions or suggestions on how Sales Cloud can improve their sales process or performance. Demoing standard features and eliciting feedback helps to quickly introduce new functionality to impress the customer by demonstrating the value and benefits of Sales Cloud, as well as engaging and involving the customer in the solution design and delivery.
References:https://trailhead.salesforce.com/content/learn/modules/salesforce-business-analyst-certification-prep/