What is the use of the Innovation and Planning IP Sprint?

• A. It is optional and rarely used in SAFe
• B. Provides estimating buffer for meeting team's objectives; a dedicated time for I&A and Release Planning activities; innovation; time for the technical infrastructure, tooling and other impediments, backlog refinement and final validation for release
• C. It doubles the number of sprints in a PI
• D. It is used only for release planning

Answer: (B)