Final answer:
Emperor Qian Long considered himself superior to King George III, asserting China's self-sufficiency and denying Britain's requests for diplomatic equality and a permanent embassy in China. Option d.
Step-by-step explanation:
Based on Emperor Qian Long's letter, it is most likely that he views himself as superior to King George III. Emperor Qian Long's opinion of King George III is derived from a context of significant military expansion, the consolidation of vast territories such as Taiwan, Mongolia, Tibet, and Xinjiang into the Chinese empire, and a strong adherence to Confucian principles and the traditional tribute system that positioned China as the 'Middle Kingdom' at the center of the world order.
This self-perception of superiority is further evidenced by Qian Long's demand for the British envoy to perform the traditional kowtow, a sign of subservience, and his clear statement that he only accepted the British monarch as a vassal, denying requests for a British embassy and asserting that China lacked nothing that Britain could offer.