Answer:
D. Serious and impassioned
Step-by-step explanation:
In "Civil Disobedience," Thoreau uses a serious and impassioned tone when describing his actions and beliefs. Thoreau is serious as he provides facts and arguments that support his point of view. However, he is also impassioned when he talks about how strong his beliefs are. He held his beliefs in such high regard he was willing to go to jail in order to defend them.