Read the sentence below to find out whether there is any grammatical error in it. The error, if any, will be in one part of the sentence. Choose the option with that part as your answer. If there is no error, choose 'D' as your answer. (Ignore the errors of punctuation, if any).
If I had known that yesterday, I will have helped him.
If I had known
that yesterday,
I will have helped him.
No error.
Correct answer is C
I would have helped him.