be onto something


I have a question on the question below:

A: I can’t believe you won the race! Good job!
B: Thanks, I’m surprised, too. I was ____________ at the end.

① onto something
② dog tired
③ testing the water
④ speaking my mind

The answer is ②. I think the situation is that B just won a running race. But the race could be a figurative expression meaning something that should be achieved. If so, how about ①? ‘Be onto something’ means ‘to have an idea or information that is likely to lead to an important discovery’. I think it would be a reasonable choice, too. (Still, I think ② is better as the answer.)

What do you think? Please let me know.

Thank you in advance,

I believe you’re over thinking that. Even if it were a figurative race, ‘I was onto something’ wouldn’t really work - for a start it indicates that he hasn’t actually achieved total success yet.