Directions: Four parts of the sentences given below have been underlined. Identify the part having an error. If no part has an error, mark (E).

If you (A) knew the facts, why (B) were you not quick to interrupt him (C) when he was so recklessly criticizing me for something I (D) did not do? (E) No error

This is a complex conditional sentence structure that is grammatically correct. 'If you knew' (second conditional) sets up a hypothetical past situation, 'why were you not quick' questions past inaction, 'when he was criticizing' describes simultaneous past action, and 'something I did not do' correctly uses emphatic 'did' in past tense.