Identify the segment in the sentence which contains the grammatical error from the given options.
I couldn't hear what was she saying due to the noise of the planes taking off.

Options

A. planes taking off
B. what was she saying
C. I couldn't hear
D. due to the noise of the

Answer

B

Explanation

"Wh-word(What. Why. When, etc.) + Subject + Verb" is grammatically the correct structure if an interrogative statement(in which a question is asked) comes within a sentence that finishes with a full stop. Hence, .what she subject) was(verb) saying. will be answer.