How Does the Reproductive System Contribute to Osteoporosis

How does the reproductive system contribute to osteoporosis?

A) Lack of sex hormone production reduces vitamin D production and decreases calcium absorption.
B) Immune cells decrease in number after puberty and reduce bone repair.
C) Excessive smoking lowers estrogen levels, which increases bone loss.
D) Calcium ions released from the bones are necessary for gamete production.
E) Decreased estrogen levels following menopause contribute to the disease.