The following sentence has been split into four segments. Identify the segment that contains a grammatical error.
One can never imagine / how hot it gets in Delhi / unless one doesn’t go / there in person.

Correct option is B

The correct option is (b) “unless one doesn’t go”.
•  The use of the negative "doesn't" creates a double negative in the sentence, which is incorrect.
•  The correct phrasing would be "unless one goes" or "if one doesn't go."