The correct answer is option A. "The message that the author wants to convey". The theme of a story can be defined as the underlying message or the "big idea" that the author wants to convey once the reader had finished reading or watching the story. The belief or idea that the author expresses usually transcendent cultural barriers, particularly for globally known novels.
Civil War. A Civil War best serve as a turning point between two historical periods. A turning point is the precise, specific or significant moment when something starts to change. Hope that helps!!!