The medullary cavity is Select one: a. empty in adult bones. b. the site where osteoblasts are found. c. lined with endosteum. d. filled with fibrocartilage and elastin fibers. e. dead space in the bone.

C - Lined with Endosteum

Explanation:

The medullary cavity, also called the marrow cavity, stores red and yellow bone marrow (or adipose tissue). It is the central cavity in the shaft of bones.

Endosteum lines the inner surface of the medullary cavity. It is a thin, vascular membrane of connective tissue with the purpose of being absorbed when a person is malnourished.