Question

brutus he is not doubted.—a word, lucillius. how he cassius received you let me be resolved. lucillius. with courtesy and with respect enough, but not with such familiar instances, nor with such free and friendly conference, as he hath used of old. brutus. thou hast described a hot friend cooling. ever note, lucillius: when love begins to sicken and decay it useth an enforced ceremony. there are no tricks in plain and simple faith; but hollow men, like horses hot at hand, make gallant show and promise of their mettle; but when they should endure the bloody spur, what conflict does brutus describe in this passage? his external conflict with cassius his external conflict with mark antony his internal conflict over killing caesar his internal conflict about the state of rome

Explanation:

In the passage, Brutus and Lucillius discuss Cassius' changed behavior towards Lucillius. Brutus is observing the cooling - off of a once - close friendship with Cassius, which indicates an external conflict between them. There is no mention of Mark Antony, internal conflict over killing Caesar, or internal conflict about the state of Rome in this passage.

Answer:

his external conflict with Cassius