As per the question, the key difference between a soliloquy and a monologue is that 'a soliloquy is spoken by a character to himself/herself while he/she is alone on stage' while a monologue is a conversational speech that is made by an individual to the audience directly.
However, both the devices are employed by the authors to reveal the thoughts, feelings, or opinions of the character to the audience but soliloquy on the one hand is regardless of the audience or speakers('Hamlet's talking to himself alone as 'to be or not to be' which reveal his thoughts aloud) and usually more precise while monologue on the other hand is a lengthy and tedious speech made by one character in the middle of a conversation to the audience deliberately which may or may not reveal the actual thoughts. Thus, <u>option A</u> is the correct answer.
