Correctly Order the Following Key Steps in the Process of Endochondral

Multiple Choice

Correctly order the following key steps in the process of endochondral ossification.
1) Chondrocytes die.
2) Osteoblasts build the bone collar on the external surface of the bone.
3) Perichondrium is invaded by blood vessels.
4) In the primary ossification center,osteoblasts replace calcified cartilage with early spongy bone.
5) Perichondrial cells differentiate into osteogenic cells then into osteoblasts.

A) 3,5,2,1,4
B) 3,1,4,5,2
C) 4,3,2,1,5
D) 3,1,2,3,5