"What started the Opium War? China's attempt to end the opium trade Britain's raising of opium prices" China's attempts to sell opium Britain's refusal to accept opium

China's attempt to end the opium trade started the Opium Wars.

Explanation:

The most important issue that started the conflict in the Opium Wars between China and Britain was the British trade in opium, as the Chinese emperor had banned the trade because of the harmful effects of opium on the population.  

Britain, on the other hand, saw the trade as very profitable, the sale of opium also helped to balance trade with China as the Chinese exported large quantities of porcelain, silk, spices and tea. With the exception of opium and silver, the Chinese were little interested in British goods. Thus, the conflict has similarities to today's Chinese trade surplus with Western countries.

the correct answer is:   the domino theory states that if one country in a region came under the influence of communism, then the surrounding countries would follow in a domino effect.