Why does Olivia refuse to marry Duke Orsino?

A.
Duke Orsino is a cruel and selfish person.

B.
She mistakes Duke Orsino for Sir Toby Belch.

C.
She is in love with someone else.

D.
Her brother has died and she is in mourning.

Question

Why does Olivia refuse to marry Duke Orsino?	
 
 A.
Duke Orsino is a cruel and selfish person.
 
 B.
She mistakes Duke Orsino for Sir Toby Belch.
 
 C.
She is in love with someone else.
 
 D.
Her brother has died and she is in mourning.

theyankee · Answer

Lol! Twelfth night. LOVE. IT.
I quote on the matter
"She doesn't like him well enough to marry him. She pleads the excuse that she is in mourning for her father and brother but as soon as someone comes along who she likes well enough to marry, namely Cesario, she drops the mourning schtick like a hot potato."