Some of the solutions are clearly just wrong. I have a PhD in Computer Science and if I am failing multiple basic addition problems, I assure you that it isn't me, the answers are wrong.
I had to do the same audio puzzles and got the first audio puzzle wrong too, and I even had my partner helping me. It is clearly just a bad test bank. Which begs the question, if the answers are wrong and there are only 3 choices, then what's the point? Regardless of whether you are human or not you are going to guess it eventually in about 5 tries, which is what it gives you before locking you out.