Answer: C) Theme.
Step-by-step explanation: In literature, the theme is the underlying message of a story, it is what critical belief about life is the author trying to convey in the writing of a novel, play, short story or poem. Usually this belief, or idea, is universal and transcends cultural barriers. The given sentence is an example of a theme (corresponding to option C) because is a message that the author of the phrase is conveying.