From Macbeth:

Which of these lines provides important information for the exposition of the play?

1. O Banquo, Banquo!/Our royal master's murder'd!

2. And, for an earnest of a greater honor,/He bade me, from him, call thee Thane of Cawdor

3. Thou know'st that Banquo, and his Fleance, lives.

4. Hail, king, for so thou art: behold, where stands/The usurper's cursed head: