Pioneer Cleaning Equipment Has Begun the Actual Design and Development

Pioneer Cleaning Equipment has begun the actual design and development including the details of manufacturing,marketing,and operations of a new floor buffing machine.Which stage in the stage-gate process comes next?

A) Stage 5, launch the product by producing and selling it.
B) Stage 4, verify and validate the process for the new product, its marketing, and production.
C) Stage 3, form a focus group to make sure the product meets user expectations.
D) Stage 2, build a business case to justify the project.