The following sentence has been split into four segments. Identify the segment that contains a grammatical error.
(1) Ganga was (2) out shopping at the mall (3) and ran over (4) her schoolmate.

The error lies in segment (3).
The phrasal verb "ran over" means to knock down and pass over someone or something with a vehicle. In the given context, Ganga was shopping at a mall and unexpectedly met her schoolmate. The correct phrasal verb for meeting someone unexpectedly is "ran into" or "bumped into". Therefore, "ran over" should be replaced with "ran into". Segment (3) corresponds to option D.