Answer: A) Universal truth.
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 phrase "The good guy should always win" is a clear example of a theme or universal truth, so the correct answer is the corresponding to option A.