Answer:
A, D
Explanation:
When you are writing an indirect proof, the first step is to temporarily assume that the opposite of what is given is true.
Because of this, that would mean that you would have to temporarily assume x>6, because the first step is to assume the wrong thing, making the answer A.
Same thing for number 16. It is giving you that n is an odd number, so you can temporarily say that n^2 is an even, since an odd times an odd it always going to equal an even, making the answer D.