Answer: B) 13/17
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Step-by-step explanation:
The "given that he is male" stated at the end means we only focus on the male column. This is because we know 100% that the person selected is male. Either we're told this by someone else, or we can determine this another way.
There are 39 males that got the flu shot out of 51 males total. The probability we're after is 39/51 = (3*13)/(3*17) = 13/17
It's effectively saying: out of every 17 males, 13 of them got the flu shot.