What is ironic about Macbeth's relationship with Banquo?

Select one:

a. Even though Macbeth feels threatened by Banquo, he tries to make Banquo feel threatened.

b. Even though Macbeth wants to remain loyal to Banquo, he knows Banquo will betray him.

c. Even though Macbeth is ashamed of Banquo, he is willing to be seen with Banquo in public.

d. Even though Macbeth fears Banquo, he masks those feelings with conversation and well-wishes.