In the tragedy of macbeth, act iii, what is the most likely reason that macbeth sends along a third murderer to join the first two in killing banquo?
a. macbeth has become terribly suspicious and trusts no one; he sends the third murderer to make certain the job gets done.
b. macbeth has funds that must be used quickly, so he hires an extra murderer.
c. macbeth suspects that banquo will bring his wife and children along with him, requiring a third murderer to provide assistance.
d. macbeth wants the third murderer to kill the other two murderers, which would result in fewer people knowing of his devious plot.