What was the outcome of the opium wars? a. british missionaries were thrown out of china. b. british merchants were forbidden to trade in china. c. british opium addicts had to find new drug sources. d. british gunboats forced china to make major concessions?

Correct D. British gunboats forced China to make major concessions.

These are the concessions China made after Britain's victory in the First Opium War:

Further context/detail on the First Opium War (1839-1842)

Britain had been trying to gain trade access to China as part of its imperial ambitions.  They found a product they could get Chinese people to buy -- the drug, opium.  The Chinese government vehemently opposed this illegal trading the British were carrying on, and the First Opium War resulted.  The British won and imposed the Treaty of Nanking on China in 1842, which compelled China to open its doors more widely to foreign trade.  The United States followed up in 1844 with The Treaty of Wangxia, which gave the US access to trade in China.  

From 1850 to 1860, conflict continued between the British and the Chinese in the Second Opium War, again with Britain prevailing and forcing China to open trade rules still further.

c) troops march forward in close formation against newer, more accurate weapons