Establish a relation for shape factor for a conical cavity with respect to itself of depth h and diameter d. The cavity is closed on its outer surface with a flat plate

• A. 1 – d/ (4 h² + d)^1/2
• B. 1 – d/ (4 h² + d ²)^1/2
• C. 1 – d/ (4 h + d²)^1/2
• D. 1 – d/ (h² + d²)^1/2