Women, who are genetically predisposed to osteoporosis, should drink a glass of milk every day. Many women substitute naturally occurring calcium sources with tablets as their daily source of calcium. However, I advise my patients to drink a glass of milk daily instead of eating calcium tablets.

Which of the following statements, if true, does most to strengthen the author’s main argument?

in this question why not option 3 and in option 1 *vitamin A* is out of context