D. Antony wants them to explain why they believed Caesar was dangerous.
<h2>Explanation:</h2>
The excerpt takes place after Antony has confronted the conspirators right after they had murdered Caesar and has been told that Caesar was too dangerous to be left alive. Antony says "you shall give me reasons why and wherein Caesar was dangerous." Antony is asking for the reason the conspirators thought Caesar was dangerous.
The speakers are only identified as a man and a girl because they are strangers in the story therfore they don't know each other just as how the reader doesn't know them because they're name isn't called.
