What is the PRIMARY role of a scrum master in agile development?

Choosing the primary development language is a technical decision made by the development team, not a responsibility of the scrum master.

Selecting the integrated development environment (IDE) is a tooling decision owned by the development team, not the scrum master.

The scrum master facilitates the agile process by helping match software requirements (from the product backlog) to the delivery plan (sprint planning and execution). They ensure the team commits to achievable work each sprint and that the backlog items are properly understood and estimated for delivery. This role bridges the gap between what needs to be built and how the team plans to deliver it incrementally.

The scrum master is a servant-leader and facilitator, not a traditional project manager; agile specifically moves away from command-and-control project management styles.