which one is correct

[vkhu]

"Their refuse(a) to help(b) is to find(c) the solution to our job(d) made us unhappy"

This is a find the incorrect word exercise. The key said A is the only answer but I think B also qualify. So which is it?
If you find any other mistake, feel free to point it out.

[emsr2d2]

"Their refuse(a) to help(b) is to find(c) the solution to our job(d) made us unhappy"

This is a find the incorrect word exercise. The key said A is the only answer but I think B also qualify. So which is it?
If you find any other mistake, feel free to point it out.

Are you sure you have copied the entire thing correctly? I have found three definite errors and one potential. Before I say what I think, please check that you have typed every single word in as it was written (including the words not in bold).

[moonlike]

You mean which one is incorrect?
There's something wrong about the sentence itself, especially at the end of it. I think the correct sentence should be like this:
Their refusal to help is to find the solution to our job [which] made us unhappy.

[emsr2d2]

You mean which one is incorrect?
There's something wrong about the sentence itself, especially at the end of it. I think the correct sentence should be like this:
Their refusal to help is to find the solution to our job [which] made us unhappy.

To be fair, I think "Which one is correct?" is a fine title - the OP wants to know what the correct answer to the question "Which is the incorrect word in this sentence?" is.

Additionally, the sentence you have posted is not correct English.

[vkhu]

Double checked. Everything is exactly how it is in my test paper (don't know if my teacher made any typo or not though, he did it once).

[Barb_D]

Certainly that "is" should be "us" and A needs to be a noun, but the entire sentence is poorly written.

[moonlike]

Yes I do agree with Barb_D.
The one that I poster earlier wasn't correct. I do apologize, although I had mentioned there's something wrong with the sentence.

[SoothingDave]

Certainly that "is" should be "us" and A needs to be a noun, but the entire sentence is poorly written.

I was going to remove the "is" completely: Their refusal to help find the solution...

[emsr2d2]

"Their refuse(a) to help(b) is to find(c) the solution to our job(d) made us unhappy"

This is a find the incorrect word exercise. The key said A is the only answer but I think B also qualify. So which is it?
If you find any other mistake, feel free to point it out.

My guesses as to the "correct" sentence:

Their refusal to help find the solution to our jobs made us unhappy.
Their refusal to help us find the solution to our jobs made us unhappy.

I really don't know what a "solution to our job(s)" is supposed to mean though. In my opinion, (a) and (d) were incorrect in the original and (c) didn't need the "to". Only (b) seems to be completely correct.