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Causation can be proved by using an

Aperson who doesn't have enough calcium in his or her diet is at risk for developing bones that are weak and break easily. this condition is known as  a.  osteoporosis.    b.  crohn's disease.    c.  celiac disease.    d.  hemophilia.

Which of these contraceptive methods would be most beneficial for a female who wishes to avoid side effects or surgery?