B: a jovial merrymaker This is the correct answer.
Sir Toby is Olivia's uncle in Shakespeare's "Twelfth Night". Maria is Olivia's waiting gentlewoman. They live with Olivia. Sir Toby likes drinking and having fun. Maria tells him to stop drinking and asks him to come home early at night because Olivia does not like these habits. Sir Toby is not very interested in Olivia's comments.
These options are not right:
A: an honorable knight. ( On the contrary, he likes drinking and enjoying himself).
C: a loathsome scoundrel. ( He is a funny character. He is not a wicked character at all).
D: a concerned uncle ( He is not serious at all. This is not reflected in this excerpt).