Sentence Correction - Verbal and Reasoning

Directions to SolveWhich of phrases given below each sentence should replace the phrase printed inboldtype to make the grammatically correct? If the sentence is correct as it is, mark 'E' as the answer.
Q1:

By such time you finish that chapter, I will write a letter.

A The time when

B By the time

C By that time

D The time

E No correction required

ANS:B - By the time

No answer description is available.