Who said the following and what does it mean?

o romeo, romeo,
wherefore art thou romeo?
deny thy father and refuse thy name,
or if thou wilt not, be but sworn my love,
and i'll no longer be a capulet. (ii. ii. 37-40)

mercutio; he is looking for that whiny, lovesick romeo again.
nurse; she is trying to find romeo so that he can spend the night with juliet.
juliet; she is not asking where romeo is, but rather why he has to be a montague.
lady capulet; she suspects that juliet is in love with romeo and will not tolerate it.