Answer:
Red bone marrow
Explanation:
Red bone marrow fills the cavity of nearly every bone in children. Hemopoietic tissue makes blood cells. Red bone marrow is found in the skull, vertebrate, ribs, sternum, proximal head of the humerus and femur.
In an adult, hematopoiesis is confined primarily to "red bone marrow."
As a result, the correct answer is red bone marrow.
