Learn English – How to respond when someone say “I hope it helps”

I would say

I'm OK, thanks.

That puts the fact that I am OK as I am (no help is needed), and then thanks.
OK is simple to understand; there is no problem.

And I prefer a simple thanks; I think thank you is too formal replying to a stranger who speaks to you first. Especially if someone was bothering you (asking if you needed help when it was obviously not necessary).

So, the situation is that both person A and person B have brought things to hand out, and both have spent hours on those things, not knowing the other was also doing it; and person B's handouts are clearly superior to person A's?

Then at this point where Person B sees person A realizing that A's efforts are completely overshadowed, B is feeling that it is unfortunate that A wasted all that time doing something that turns out fruitless. Either there is empathy involved (B feels bad because he knows that A feels bad) or there is not (B merely regrets the lost opportunity to have A be doing something useful, or B is happy to outshine A).

If there is some level of empathy involved (and since person B feels "apologetic", it seems that there must be some), then either "felt bad for" or "felt sorry for" would be appropriate and idiomatic.