Why does Juan think he's making the right choices by sending the letter to Mariana?

in june, we will have been married for eighteen months. (i am assuming this is what you want? the sentence, as you have presented it, is grammatically incorrect--   you want it corrected, yes? )

answer: inference

explanation:

an inference can be understood as a conclusion to which a person is able to get based on reasoning. it is the same as a deduction, a guess, an assumption.   in the sentence presented, the conjunction "but" gives the readers an idea of contrast, and, therefore, allows them to induce that despite the opponent's characteristics, andrea had something different that made her win.

the answer is d)to persuade the troops that she is a capable commander