Answer: D) They fear they will be murdered.
Step-by-step explanation: In the given passage from the act II, scene III of "Macbeth" by William Shakespeare we can see a conversation between Malcolm and Donalbain, where they discuss the fact that they need to leave Scotland in order to be safe, Malcolm is going to England and Donalbain is going to Ireland, they think that going in separate ways will keep them safer, they are leaving because they fear they will be murdered.