D, because that one starts with "why" which automatically opens it up for an argument. While the others are just simply statements or just a basic question.
Explanation:
Opium was first introduced to China by Turkish and Arab traders in the late 6th or early 7th century CE. Taken orally to relieve tension and pain, the drug was used in limited quantities until the 17th century. At that point, the practice of smoking tobacco spread from North America to China, and opium-smoking soon became popular throughout the country. Opium addiction increased, and opium importations grew rapidly during the first century of the Qing dynasty (1644–1911/12). By 1729 it had become such a problem that the Yongzheng emperor (ruled 1722–35) prohibited the sale and smoking of opium. That failed to hamper the trade, and in 1796 the Jiaqing emperor outlawed opium importation and cultivation. Despite such decrees, however, the opium trade continued to flourish.
Early in the 18th century, the Portuguese found that they could import opium from India and sell it in China at a considerable profit. By 1773 the British had discovered the trade, and that year they became the leading suppliers of the Chinese market. The British East India Company established a monopoly on opium cultivation in the Indian province of Bengal, where they developed a method of growing opium poppies cheaply and abundantly. Other Western countries also joined in the trade, including the United States, which dealt in Turkish as well as Indian opium.
Britain and other European countries undertook the opium trade because of their chronic trade imbalance with China. There was tremendous demand in Europe for Chinese tea, silks, and porcelain pottery, but there was correspondingly little demand in China for Europe’s manufactured goods and other trade items. Consequently, Europeans had to pay for Chinese products with gold or silver. The opium trade, which created a steady demand among Chinese addicts for opium imported by the West, solved this chronic trade imbalance.
