Why does act 3 scene 1 of Julius Caesar be considered the climax of the play

Act III of Julius Caesar might be considered the climax, or most intense part or the play, because this is where all of Brutus' conflict comes to a head. It is also the longest act of the play. The act begins with Caesar's arrival in the Capitol. Almost immediately, he is approached by Artemidorus, who offers him a letter of warning about the conspirators. He begs Caesar to take the letter because it pertains to his well-being. However, saying that his personal matters are the least of his concerns, Caesar refuses to take the letter. Meanwhile, one man wishes Brutus and Cassius good luck in their "enterprise," causing Cassius to wonder if their plans have been discovered. One of the conspirators pulls Antony away on business so that he won't interfere in the conspiratorial plans.