Final answer:
Celia's method of opening the door to save Opium is metaphorically linked to the historical actions of China during the First Opium War, where efforts to stop opium trade led to Britain imposing Opium on China through military action, resulting in treaties that opened China's ports to opium trade.
Step-by-step explanation:
The main answer to how Celia opened the door to save Opium revolves around the historical events of the First Opium War. The Opium War was sparked by conflicts between China and Great Britain over the opium trade. Chinese authorities, including Lin Zexu, attempted to halt the influx of opium by confiscating and destroying the drug, which was causing widespread addiction and economic turmoil in China. However, these efforts resulted in military retaliation by Britain, which aimed to protect its opium commerce interests and led to China's defeat. The culmination of the war forced China to open its ports to foreign trade, including opium, under unequal treaties such as the Treaty of Nanjing. This inflicted lasting damage on China's society and economy, undermining the Qing dynasty's authority.