Which correctly defines soliloquy? whispering in hushed tones in an effort to hide a discussion with others shouting and yelling dialogue to other characters in a play talking out loud to the entire audience hoping to be heard speaking to one's self out loud without regard to who might be listening

The answer is: 
Speaking to one's self out loud without regard to who might be listening

A soliloquy is a way of communicating the actors thoughts and feelings to the audience as if they were just reflections by the actor himself, almost like reading the actor's mind. The actor speaks out loud, but she is either alone or presumably unheard by other characters on stage. She is not addressing the audience, but the play is giving the audience a window into the actor's mind. 

a) ,

Explanation:

It cannot be b) because that is used like a full stop

It's definitely not c because it's not a simple sentence.