THE CORRECT ANSWER IS (B). THE PASSAGE POSITS THE FOLLOWING SIMPLE...

18. The correct answer is (B). The passage posits the following simple argument: If both

of two conditions (exposure to the nuclear testing at an age less than 10 years) are true,

then a particular result (death before age 50) is certain. Given that this argument is

true, any person alive today who resided in the town during the testing (and therefore

was exposed to the resulting radiation) must have been at least 10 years old at the time.

Here’s the essence of the reasoning:

Premise: If both A and B, then C.

Premise: Not C.

Conclusion: Not both A and B.