Final answer:
Women begin to lose bone mass after it peaks around the age of 30, with a more rapid loss starting around the age of 50 due to menopause. The correct answer is C) 30.
Step-by-step explanation:
The question asks at what age women begin to lose bone mass. Based on the information provided, bone density peaks at about 30 years of age in both males and females. However, women tend to lose bone mass more rapidly than men.
The most significant loss in bone mass for women starts at about 50 years of age, which is around the time of menopause. This is due to the reduction in estrogen production, which is essential for promoting osteoblastic activity and bone matrix production. Therefore, the answer is C) 30, as bone mass decreases after peaking at this age, and the rate of bone loss increases significantly after the age of 50 due to menopause.