Answer :
D. Caliban knows that Prospero has powerful magic, so he tells Stephano and Trinculo that Prospero takes a nap at the same time every day. He tells them to burn all of his books first, so that he does not have his magic anymore, and then to bash his brains in. He makes sure to tell them not to kill Miranda, because he thinks she is beautiful and Stephano vows to kill Prospero and make Miranda his queen.