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 am sure that all my monthly expenses would exceed the income if I do not economic.
I am sure that all my monthly expenses
would exceed the income
If I do not economic
No error.
Correct answer is C
If I do not economise