单选题 Mrs. Cray, an African American, is admitted to the hospital after sustaining a hip fracture. She is 5 ft. , 4 inches tall and weighs 96 lbs. She has five children and has used estrogen replacement therapies for 10 years. She told the nurse that she "just stepped forward and fell. " The results of her bone density tests indicate she has osteoporosis. Which of the following is the greatest risk factor for osteoporosis for this woman?
A. Her long-term use of estrogen.
B. Her weight.
C. Her family.
D. Her race.

【正确答案】 B

【答案解析】Heavier body weights and some body fat stress bones and promote their maintenance. Osteoporosis is most often associated with being underweight. Women who are thin throughout their lives are twice as likely to develop hip fractures.