Answer:
soliloquy: talking to yourself
monologue : talking to others
Explanation:
A monologue is when there's more than one party involved, like two people talking to each other, but essentially all the talking is done by one person. Imagine a parent scolding a child, and the child doesn't respond. Or a comedian performing alone on stage in front of an audience. There's only one person speaking... but to someone else.
A soliloquy also implies only one person talking... but it's mostly in cases where there's no other participant in the communication. Like when you're talking to yourself. So, there's only one person talking again, but not to any one else.
Allegory: Noun.
A story, poem, or picture that can be interpreted to reveal a hidden meaning. Usually a moral or political one.
Example: The allegory of the book Red Riding Hood is not to trust strangers.
It can also be a symbol.
The answer is B.
I'm not 100% sure on this one, so I'm just gonna go through the list!
"Juliet's demand that Romeo constantly send her messages is so unrealistic that the audience forsees she will be disappointed." I don't see how that builds tension, so this one can be eliminated.
"Romeo and Juliet's love for each other is so deep and pure that any audience would know problems will arise." I don't see how this builds tension either, only if the reader is pessimistic. I think this one can be eliminated too.
"The Nurse's sudden entrance, communicating a sharp warning, alerts the characters and audience to danger." I feel that this one very clearly signals tension, so this is an option.
"Romeo and Juliet's disagreement about whether the bird is a nightingale or a lark is symbolic of the unknown threat that approaches." I can see how this one can build tension as it is a bit of an argument/disagreement, but I don't think it creates more tension than the Nurse, so I'd go with your third option, "The Nurse's sudden entrance, communicating a sharp warning, alerts the characters and the audience to danger."!
Hope I helped!
(tl;dr: the answer should be the third one aka the one that mentions the nurse) :D
I would say the whole sentence, starting with the relative noun in the clause, is used as C) subject of this whole sentence.