Which of the Following Involves Respiratory System Activity That Contributes

Multiple Choice

Which of the following involves respiratory system activity that contributes to osteoporosis?

A) Lack of oxygen reduces vitamin D production and decreases calcium absorption.
B) Mucosal cells of the respiratory tract release chemicals that inhibit tissue repair.
C) Excessive smoking lowers estrogen levels, which increases bone loss.
D) Calcium ions released from the bones are excreted through exhaled air.
E) Decreased oxygen levels contribute to the disease.