Anti-climax greatly annoys readers. If they're going to put the time into reading something because it has an engaging plot, they're going to expect an equally interesting climax to arise out of that plot. If the readers don't get that, they're going to feel cheated.
The answer is the amputation of the lieutenant's arm. None of the other options are events in the story. The lieutenant returns home and we don't know the outcome of the battle. There is also no evidence he was ever ill.
I think it's A. I'm not 100% sure.
before "The people"
On the sidewalk, the people stared at the fast-moving car.
The sentence keeps meaning and makes sense.
