Which of these contraceptive methods on its own is least likely to prevent pregnancy? A. Condoms
B. Surgical sterilization
C. Spermicides
D. Oral contraceptives

C

Explanation:

By itself, spermicide prevents just 72% of pregnancies, the least effective of any major contraceptive measure. Because of its poor success rate, spermicide is often used in conjunction with other contraceptives such as patches and condoms.

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