The answer is b. When
Macbeth kills Banquo, he no longer hesitates to kill anyone who he deems a threat
to his rule as king. Before he killed
King Duncan, he was still unsure if he will do so or not until his wife shamed
him into killing him. When it came to
killing Banquo, he did it out of his own will. This was followed by killing
Macduff’s wife and son since he could
not kill Macduff himself. He no longer
cared so long as he stayed in power.
