can't be a or b because you can't reflect with the x or y axis or else the resulting triangle would be different
cant be d because if it was translated, then a' and b' wouldnt be in opposite directions (if you didnt get that part, i mean that first, the order was a then b, but then the order changed to b' then a')
so it has to be c (this also makes sense because if you rotate something some points might flip sides)
hope this helps and I hope you get through the ABSOLUTE WORST part of geometry!
