mpletion Status: QUESTION 1 What type of study design was implemented? a. Cross-sectional study Ob. Cohort Study Oc. Case-control study Od. Randomized clinical trial QUESTION 2 Which choice best describes the reasons and principle hypothesis for this study? Oa. 1. Osteoporosis is a not major cause of injury, loss of independence, and death. 2. There is no evidence showing that vitamin D supplements slow bone loss in postmenopausal and elderly women. 3. There is well documented knowledge with respect to the effect of calcium and vitamin D supplements affects hip and other fractures. 4. No evidence shows that the risk of fractures among older women did not change with calcium plus vitamin D supplementation. 5. This study aims to test whether calcium plus vitamin D supplementation would reduce the risk of hip fracture among women receiving the treatment compared to the placebo. Ob. 1. Osteoporosis is a major cause of injury, loss of independence, and death. 2. The authors don't know if there is evidence that calcium plus vitamin D supplementation has any effect on fractures. 3. This study aims to test whether calcium plus vitamin D supplementation would reduce the risk of hip fracture among women receiving the treatment compared to the placebo. Oc. This is a completely novel problem, a rationale is not required. Od. 1. Osteoporosis is a major cause of injury, loss of independence, and death. 2. There is evidence showing that vitamin D supplements slow bone loss in postmenopausal and elderly women. 3. There is limited knowledge with respect to the effect of calcium and vitamin D supplements affects hip and other fractures. 4. Some evidence shows that the risk of fractures among older women did not change with calcium plus vitamin D supplementation. 5. This study aims to test whether calcium plus vitamin D supplementation would reduce the risk of hip fracture among women receiving the treatment compared to the placebo. 1 po QUESTION 3