Why is speed (in running) important, why do we need speed?

Which statement best explains the relationship between diet and osteoporosis? a. cholesterol blocks calcium from reaching bone cells. a diet that is high in cholesterol can lead to osteoporosis. b. calcium and phosphorus build strong and flexible bones. a diet that lacks these nutrients can lead to osteoporosis. c. protein and iron build strong and flexible bones. a diet that lacks these nutrients can lead to osteoporosis.