Read the following sentence to find out whether there is an error in any part. No sentence has more than one error. If you feel there is no error in a sentence, choose ‘No error’.
Unless you apologized I shall punish you.

Correct option is B

Option (b) contains an error.
Explanation: “Unless” introduces a condition in the present or future, so the correct verb form is “apologize” (present simple), not “apologized” (past).
Grammatical rule used:
�� In conditional sentences with “unless,” use present tense to refer to future possibilities.
Example: Unless you work hard, you will fail.
�� Information Booster: "Unless" = “if not.” Don’t use past tense if the condition refers to future.