Question

summarizing condom effectiveness for preventing hiv
the us centers for disease control and prevention reports that condoms have been shown to be effective in preventing hiv infection. in a two - year study of couples in which one partner was hiv - positive and the other hiv - negative, no hiv - negative partner was infected when condoms were used correctly and consistently. among couples in which condom use was inconsistent, 10 percent of the hiv - negative partners became infected.

• \condom effectiveness\

which statement best summarizes the effectiveness of condoms in preventing hiv infection?
○ condoms are always effective.
○ condoms are effective if used correctly.
○ condoms are effective if used consistently.
○ condoms are effective if used correctly and consistently.

Explanation:

The text states that condoms are effective when used correctly and consistently (no infections in such cases) and ineffective when used inconsistently (10% infection rate). So we check each option against this.

• "Condoms are always effective" is wrong as there's a 10% infection rate with inconsistent use.
• "Condoms are effective if used correctly" misses the consistency part.
• "Condoms are effective if used consistently" misses the correct - use part.
• "Condoms are effective if used correctly and consistently" matches the text's description.

Answer:

Condoms are effective if used correctly and consistently.