How does a soliloquy differ from a monologue?

Question

A. A soliloquy is always sad, while a monologue is always happy.
B. A soliloquy involves a solitary speaker, while a monologue is delivered by multiple people.
C. A soliloquy is not intended to be heard by other characters, while a monologue is.
D. A soliloquy offers insights into a character’s thoughts, while a monologue does not.

Answer 1

C. A soliloquy is not intended to be heard by other characters, while a monologue is.