Question

the membrane that lines the medullary cavity is the _____.
endosteum
periosteum
meniscus

Explanation:

The endosteum is the membrane that lines the medullary cavity of a bone. The periosteum covers the outer surface of bones, and the meniscus is a C - shaped fibrocartilaginous structure in joints, not related to the medullary cavity lining.

Answer:

A. endosteum