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 shall certainly write you when I shall reach New Delhi.
I shall certainly
write you
when I shall reach New Delhi.
No error.
Correct answer is C
when I reach New Delhi.