Which of the following incidents in the tragedy of macbeth, act v. is most clearly a harbinger of macbeth's downfall? explain
your response.
a the gentlewoman's remark about lady macbeth, "she has a light by her continually
b. macbeth's calling his servant a "lily-livered boy"
macbeth's remark, “throw physic to the dogs"
d. the messenger's remark. "i looked toward birnam, and anon, methought, the wood began to move"