Which of the Following Statements Concerning Osteoporosis Are True

Which of the following statements concerning osteoporosis are true?

A) Data show that tobacco use is a significant risk factor for bone loss.
B) Osteoporosis is often called a "silent disease" because neither pain nor specific symptoms are associated with this condition.
C) The spine, hips, and wrists are especially vulnerable to osteoporosis's effects.
D) Amenorrhea (lack of menstrual periods) or diseases that may lead to amenorrhea, such as anorexia nervosa, may have a protective effect against osteoporosis.