Final answer:
An (C) 'aside' is a short speech by a character to the audience that others on stage do not hear, distinguishing it from a soliloquy, monologue, and dialogue.
Step-by-step explanation:
The short speech by a character that only the audience can hear is known as an aside. This dramatic device is different from a soliloquy, monologue, and dialogue. An aside is a brief comment or speech made by an actor to the audience that the other characters on stage are not supposed to hear.
Conversely, a soliloquy is a longer speech where a character conveys his or her inner thoughts, typically alone on stage, whereas a monologue is a speech given by a character regardless of other characters' presence. Dialogue, on the other hand, involves a conversation between two or more characters. Each of these elements plays a crucial role in advancing the plot and revealing character details within a play.