Answer: Their fight shows that they are united and supportive of each other's choices.
Explanation: In ACt IV, Scene I of "The Tragedy of Julius Caesar" by William Shakespeare, Mark Antony and Octavius' fight about the value of Lepidus develops the plot of the play because their fight shows that they are united and supportive of each other's choices. Octavius thinks that Lepidus is a valiant soldier. Mark Antony thinks he is like his horse, he can only do what he is told. They respect each other's opinion and continue to talk about fighting the conspirators.