The team cannot agree on the level of effort required to complete a task. What should the project manager do?

The correct approach is to facilitate a discussion where each team member explains their rationale. This allows for a deeper understanding of assumptions, potential risks, and different perspectives that led to their estimates. By understanding the 'why' behind the numbers, the team can identify misunderstandings, clarify scope, and ultimately converge on a more accurate and agreed-upon estimate through consensus. Simply averaging estimates ignores valuable insights and potential flaws in individual estimations. Telling the team to resolve it without guidance is abdication of leadership. Deciding unilaterally undermines team empowerment and ownership.