During a sprint retrospective in an agile project, two team members engage in a heated argument about the team's velocity calculation methodology. The disagreement is escalating and other team members are becoming uncomfortable. What should the project manager do FIRST?

Immediately end the retrospective and schedule individual meetings with both team members

Facilitate a structured discussion to understand both perspectives and guide the team toward consensus

Make an executive decision on the velocity calculation method to resolve the conflict quickly

Ask the Scrum Master to handle the conflict while continuing with other retrospective items