In which graph does y vary directly as x? it’s not c, i got it wrong.

Hello there!

Based on my research and information, I really believe that (option a) would actually be your correct answer. I believe this basically because sense the letter k is always constant, we would only divide this by what it is, which is y, and from these, your solution would always look like your (option a). Please inform if correct.
I hope this helps you!