Why Does an Adult Not Have as Many Bones as a Child

Multiple Choice

Why does an adult not have as many bones as a child?

A) because osteoporosis leads to bone loss with age
B) because some separate bones gradually fuse with age
C) because many bones are replaced by cartilage with age
D) because bones are reabsorbed with age
E) because osteoclast activity overcomes osteoblast activity with age