What is the main difference between compact and spongy bone?

A. Compact bone is found in the epiphysis, while spongy bone is found in the diaphysis.

B. Compact bone is dense and solid, while spongy bone has a porous, honeycomb structure.

C. Compact bone contains red marrow, while spongy bone contains yellow marrow.

D. Compact bone is flexible, while spongy bone is rigid.