The Scrum Master is responsible for promoting and supporting Scrum, which includes helping the Scrum Team and the organization understand and enact Scrum values, principles, and practices. The Scrum Master should offer guidance that:

Addresses the root cause of the conflict, not just the symptoms or the consequences.

Empowers the Scrum Team to self-organize and collaborate effectively, without relying on external intervention or authority.

Fosters a culture of transparency, inspection, and adaptation, where feedback is welcomed and used to improve the product and the process.

Focuses on delivering value to the customer and meeting the Sprint Goal, not on following a fixed plan or satisfying individual preferences.

Therefore, the best option is to address why requirements change during the Sprint Retrospective ©, which is an event that allows the Scrum Team to inspect how they worked together and create a plan for improvements. The Scrum Master should ask the Developers and the Product Owner to talk about why the requirements are changing and consider the impact on value during this discussion. This will help them understand each other’s perspectives, clarify their expectations, and align their goals.

The other options are not appropriate because they:

Take everyone to a 2-day off-site event to relax and re-align (A), which may be a nice gesture, but does not solve the underlying problem or help the Scrum Team improve their collaboration skills. It may also be seen as a distraction or a reward for poor performance.

Ask each person’s functional manager to instruct their employees that they must collaborate better, or be removed from the team (B), which undermines the self-organization and autonomy of the Scrum Team and introduces a threat of punishment that may damage trust and motivation. It also violates the Scrum value of respect and the principle of servant leadership.

Ask for a project manager or other external resource to mediate and temporarily take over for the Product Owner (D), which creates a dependency on an outsider who may not have the necessary knowledge, authority, or vision to manage the product. It also violates the Scrum role of the Product Owner and the principle of single-wringable-neck.

References: : [Scrum Guide], The Scrum Master : [Scrum Guide], The Sprint Retrospective : [Scrum Guide], The Product Owner : [Scrum Guide], The Developers : [Scrum Guide], Scrum Values