Beginning in the 1830s, what commodity did british merchants use to increase access to chinese markets?

Opium. It was easily produced in neighboring British-controlled India and was highly addictive. When China banned the trade, Britain declared war on them. After the war China had to open major port cities for trade and give the British the coastal city of Hong Kong.

option a

explanation:

to cleberate the end of their war

just finished this it is b. centrifugal force