For Question 3, the best answer that explains the irony of the king’s comments about Inverness is:
a - This is ironic because Duncan says how pleasant the palace is because he doesn’t know what the Macbeths are planning.
Duncan's naïve observation contrasts sharply with the sinister intentions of Macbeth and Lady Macbeth, creating the irony.
For Question 4, the quotation that best supports this answer is:
c - “This castle hath a pleasant seat. The air/ Nimbly and sweetly recommends itself/ Unto our gentle senses.”
This quote reflects Duncan's view of the castle as pleasant and welcoming, which is ironic given the actual treachery that is about to take place.