I am so glad you asked this question, and I know the answer.
When I first took this test, I was confused because me school did not explain this play, or foreshadowing.
The answer to this question is D (Brutus: What means this shouting? I do fear the people choose Caesar for their king).
I'll tell you why this is the answer: this is the only one that makes sense because this means he might be plotting something...like the murder of Caesar...which actually did wing up happening.