According to the Professional in Business Analysis (PMI-PBA) Examination Content Outline1, one of the tasks of a business analyst is to "communicate and manage solution scope boundaries and approval processes to stakeholders" (Task 5.2). This implies that any changes to the solution scope should be approved by the relevant stakeholders and follow a predefined process. The PMBOK Guide2 also states that "the project manager, project team, and other stakeholders are responsible for determining how the project scope will be managed, how scope changes will be integrated into the project, and who will approve the scope changes" (Section 5.6.1). Therefore, the project manager should advise the team not to engage in modifications unless it follows the proper change approval process, as this would ensure that the scope is controlled and aligned with the project management plan. References:
* 1: Professional in Business Analysis (PMI-PBA) Examination Content Outline
* 2: A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Sixth Edition

Organizing more frequent sprint reviews with a broader audience is a key practice in Agile methodologies to ensure that the increments meet the end users' quality requirements. This approach allows for continuous feedback and collaboration, which are essential for Agile teams. It enables the team to present the increment to stakeholders, including end users, and receive immediate feedback that can be incorporated into the next sprint. This aligns with Agile principles of customer collaboration and responding to change123.
References:
Agile QA Process: Principles, Steps, and Best Practices1
Best Practices for an Agile QA Process2
How to Ensure Quality in Agile: Best Practices and Tools3

The project manager should first assess the current state process to understand the existing problems, needs, and opportunities for improvement. This will help to define the scope of the digitization project, which is the sum of the products, services, and results to be delivered by the project. Digitizing the current state process exactly as defined, redefining the current state process to scope the supporting software, or developing the software that will support the current state process are all actions that should be done after defining the project scope, not before. References: PMBOK Guide 7th Edition, page 71; Agile Practice Guide, page 37.

The agile leader should speak directly with the team member about improvements and commit to an agreed- upon time frame. This is the best option because it shows the agile leader's respect and empathy for the team member, as well as the willingness to help them overcome their challenges and grow their skills. By speaking directly with the team member, the agile leader can also understand the root cause of the problem, provide constructive feedback, and agree on a realistic and achievable plan for improvement. This option also aligns with the agile values of "individuals and interactions over processes and tools" and "responding to change over following a plan"1.
The other options are not as effective as option D. Option A is not supportive and may demotivate the team member and create resentment. Option B is not appropriate and may embarrass the team member and lower the team morale. Option C is not relevant and may not address the team member's specific needs and gaps. References: 1: Agile Manifesto, [Manifesto for Agile Software Development]