Why is cassius so intent on convincing brutus to join with the conspirators?

a.
brutus is a well-known assassin who can teach the conspirators how to do the job correctly.

b.
brutus knows where caesar lives and can the conspirators strike caesar in his home.

c.
brutus is highly respected, and cassius knows that joining with brutus will give the conspirators credibility.

d.
brutus wants to be king, and cassius knows that brutus will do anything for power.