What is ironic about Capulet's statement that the city is "bound" to the Friar?

Capulet thinks the city should be bound to the Friar because he has talked Juliet into marrying Paris. (Why the whole city should care I don't know.) Of course the audience knows that this Friar whom Capulet is praising has actually talked Juliet into faking her death so she won't have to marry Paris.

i feel like it is actually b.

the answer is not b, and i don't think its a, so i choose either man's identity is found within the traditions of his ancestors   or language is a powerful tool, tell me if i was wrong or right by the way