Directions: Identify which part of the given sentence contains a grammatical error. When I saw Arnab he said he had taken his driving test yesterday.

Step-by-step solution

The error lies in part (3) of the given sentence. The past perfect tense 'had taken' is incorrectly used with the definite past time adverb 'yesterday'. According to standard grammatical rules, the simple past tense should be used to describe an action that occurred at a specific time in the past indicated by words like 'yesterday', 'last week', or 'ago'. Therefore, 'had taken his' should be replaced with 'took his' to make the sentence grammatically correct.