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).
I fail to understand why he replied in negative when the proposal was in his favour.
I fail to understand
why he replied in negative
when the proposal was in his favour.
No error.
Correct answer is A
I failed to understand