Question

The questions below refer to the selection "The Tragedy of Julius Caesar, Act II.” An attempt to warn Caesar of the conspiracy occurs in the form of a
message Portia sends with Lucius.
letter from Artemidorus.
confession from Brutus.
conversation with Cicero.

Answer 1

The second is definitely the right one. Teacher Artemidorous knew about Brutus'  conspiracy and in order to warn Caesar he wrote a letter where he says "Caesar, beware of Brutus; take heed of Cassius". He  mentioned that Brutus is not loyal at all and that he is going to get a profit from the accident that may happen with Caesar soon which his guards might not prevent.