Which of these summaries best describes act i of macbeth?
a) macbeth and banquo meet the three witches, after which they hatch a plot to kill king duncan.
b) macbeth is determined to murder duncan after he meets the witches, but lady macbeth protests against the idea.
c) macbeth and banquo meet the three witches, who prophesy to them. later, macbeth and lady macbeth decide to kill duncan.
d) king duncan awards banquo with the title of the thane of cawdor for his bravery. this enrages macbeth, who decides to kill duncan.