I believe subtext would be the best option, simply becasue the plot is more of the main idea and what is going to happen where the subtext is kind of what the author wants you to get out of it.
His feeling were both positive toward slaves and negative towards slavery.
The music is really loud or It can be felt.
Well, it tells you that thoughts (which express theme) and emotions (which express mood) are closely connected, so d. theme and mood are closely linked.
