According to the documentation of Professional Scrum Product Owner™ (PSPO I), the Scrum Master should consider the following two answers in this situation:

B. The benefit of Developers figuring out a solution for themselves.

D. The ability of the Scrum Teams to produce integrated Increments.

The reason for choosing these two answers is that they align with the Scrum Master’s role as a servant leader, coach, and facilitator of the Scrum Team12. The Scrum Master should not interfere with the team’s autonomy and creativity, but rather support them in achieving their goals and delivering value to the stakeholders12. The Scrum Master should also ensure that the team can work together effectively and deliver a potentially releasable Increment at the end of each Sprint12.

The other two answers are not as relevant or appropriate for this situation:

A. The need to have enough work to keep all Developers busy.

C. The desire to maintain a stable velocity.

The need to have enough work to keep all Developers busy is not a valid reason for involving an external specialist in the Scrum Team12. The Scrum Team should be self-organizingand cross-functional, meaning that they can decide how to best accomplish their tasks without depending on external resources or expertise12. Moreover, having too much work can lead to scope creep, which can compromise the quality and value of the product12.

The desire to maintain a stable velocity is also not a valid reason for involving an external specialist in the Scrum Team12. Velocity is a measure of how much work can be completed by the team in a given time period, such as a Sprint or a release cycle12. It is not a fixed or objective number, but rather depends on various factors such as team size, complexity, skills, motivation, etc.12. Therefore, having an external specialist does not guarantee that the team will maintain a stable velocity, but rather may introduce additional challenges such as communication barriers, coordination issues, dependency risks, etc.12.

I hope this answer helps you understand how to apply your knowledge of Professional Scrum Product Owner™ (PSPO I) objectives and content in this situation. If you have any further questions or feedback, please let me know. Thank you for using Bing!????