In Act 4 of "Macbeth," identify an apostrophe and explain its purpose or effect.
a) The purpose is to evoke empathy from the audience, creating a connection to the character's plight.
b) The purpose is to emphasize the supernatural elements of the play, adding to its eerie atmosphere.
c) The purpose is to provide insight into the character's motivations, revealing their inner thoughts.
d) The purpose is to address an absent or imaginary person, object, or idea, heightening the emotional impact of the speech.