After reading the tragedy of julius caesar, why would the reader consider mark antony the antagonist of brutus?

a. brutus and mark antony are both protagonists because they do not cause problems for each other.

b. cassius is the antagonist; mark antony is the protagonist.

c. only octavius is an antagonist to brutus; mark antony plays a minor role in the play.

d. mark antony poses problems for and works against brutus, who strives to live the republic's ideas.