The correct answer is A (individually and then discuss their individual ratings as a team) because, according to NCMA CMBOK, effective source selection requires both independent evaluation and collaborative consensus-building. This approach ensures objectivity while leveraging the collective expertise of the evaluation team.

CMBOK emphasizes that evaluators should first independently review and assess proposals against the stated evaluation criteria. This prevents bias, groupthink, or undue influence from dominant personalities within the team. Each evaluator develops their own ratings, findings, and assessments based on the proposal's merits.

After individual evaluations are completed, the team convenes to discuss their findings, reconcile differences, and develop a consensus evaluation. This discussion focuses on identifying strengths, weaknesses, deficiencies, and risks, leading to a unified and well-supported assessment of each proposal.

Option B is incorrect because simply averaging ratings does not ensure meaningful evaluation or discussion. Option C is incorrect because proposals should not initially be evaluated as a group without independent analysis. Option D is partially correct but incomplete, as it omits the critical step of independent evaluation.

CMBOK highlights that this structured process enhances fairness, transparency, and defensibility, ensuring that award decisions are based on thorough and unbiased evaluation practices.