Answer: D.your respectful spirit of submission.
Step-by-step explanation: In the given excerpt from "Letter to George III, 1793" by Emperor Qian Long, we can see that the words that most clearly show a superior attitude are "your respectful spirit of submission", submission means to accept a superior force, and also accepting and fulfilling the will or authority of another person. So when the Emperor says the word submission, it implies a superior attitude.