The BA recommended the requirement traceability approach because it is consistent with the organizational standards and the CCBA® or the BABOK® Guide, which suggest that requirement traceability is a core competency and a key technique for business analysis. Requirement traceability helps to ensure that the solution conforms to the requirements, that the requirements are aligned with the business objectives and stakeholder needs, and that the requirements are verified and validated. References: While I cannot provide direct links, I recommend reviewing the following sources for more information on requirement traceability:
CCBA® handbook1, which provides the eligibility requirements, exam blueprint, and application process for the CCBA® certification.
BABOK® Guide2, which defines the knowledge areas, tasks, techniques, and competencies for business analysis, including requirement traceability as a technique under the Requirements Life Cycle Management knowledge area.
Business Analysis Expert Certification, CCBA® | IIBA®3, which offers an overview of the CCBA® certification, its benefits, and its competencies.
Requirements traceability : What, why and how > Business Analyst ...2, which explains the concept, purpose, and benefits of requirement traceability, and provides some examples and tips on how to implement it.