The project manager should use a collaborative or problem-solving strategy to resolve this conflict in the meeting. This strategy involves finding a solution that fully satisfies the concerns of both parties and results in a win-win outcome. The project manager should ensure that both managers understand the requirements and the impact of their contradiction on the project scope, quality, and schedule. The project manager should also facilitate a constructive dialogue between the managers and help them identify and evaluate alternative solutions that can meet the project objectives and satisfy the stakeholders. The project manager should avoid imposing a decision or favoring one side over the other, as this may lead to resentment, resistance, or further conflict.

Option A is not a good choice, because it does not address the root cause of the conflict or seek a resolution. It may also create confusion, ambiguity, or inconsistency in the project deliverable, as well as increase the project risk and complexity.

Option B is not a good choice, because it does not involve the managers in finding a solution or consider their interests and needs. It may also create dissatisfaction, frustration, or hostility among the managers, as well as affect the project quality and stakeholder satisfaction.

Option D is not a good choice, because it does not foster a cooperative or integrative approach to resolving the conflict. It may also create a competitive or adversarial atmosphere in the meeting, as well as ignore the non-monetary or intangible factors that may influence the managers’ preferences and expectations.