Key governance factors for release and instance management include:

B. Operating model and development approach: Define the organization's approach to development (e.g., Agile, Waterfall), release cycles, and how different teams collaborate on the platform.

C. Platform scope and deployed applications: Clearly define the scope of the ServiceNow platform within the organization and the applications that will be deployed. This helps with planning and resource allocation.

E. Number and purpose of instance environments: Establish a clear instance strategy, including the number of instances (dev, test, prod, etc.), their purpose, and how they are used to support development and deployment processes.

Why not the other options?

A. Release performance and instance usage analytics: While these are important for monitoring and optimization, they are not primary governance factors.

D. Day-to-day instance performance metrics: These are operational metrics, not directly related to governance decisions.