The system requirements verification matrix is a tool that helps to track the status of each requirement throughout the project lifecycle. It shows whether a requirement has been accepted, rejected, deferred, or implemented. The business analyst should have used this tool to record the reasons for rejection or deferral of any requirement, as well as the impact and resolution of such changes. This way, the business analyst can easily provide a list of rejected and deferred requirements to the project manager upon request. Setting up a change control board is not enough to track the number of rejections, as it does not provide a detailed record of each requirement's status. Limiting the number of rejected requirements on the project is not a realistic or helpful approach, as some requirements may be invalid, incomplete, or conflicting and need to be rejected or deferred for the benefit of the project. Spending more time up-front reviewing the requirements may reduce the chances of rejections, but it does not guarantee that no requirement will be rejected or deferred later in the project. References: Business Analysis for Practitioners: A Practice Guide, page 161-162; PMI Professional in Business Analysis (PMI-PBA)Examination Content Outline, page 19.

Interviewing stakeholders to clearly define the problem is the most important action to contribute to the success of the initial stage of the project. Interviewing is an elicitation technique that involves asking questions to stakeholders to gather information about their needs, expectations, issues, and goals. Defining the problem clearly helps to establish the business need, the project scope, and the solution approach. References:
PMI Guide to Business Analysis, Chapter 6, Section 6.3.2.5; PMI Professional in Business Analysis (PMI- PBA) Examination Content Outline, Domain I: Needs Assessment, Task 2.