The discovery of quinine was essential to the British Empire because it

To stop malaria

Explanation:

The discovery of quinine was a major advancement that was crucial to European imperialism and expansion. Quinine controlled attacks of malaria which, until the 1800s had decimated Europeans attempting to colonize in mosquito infested land.

b. major john c. frémont led a rebellion called the bear flag revolt.

explanation:

during the bear flag revolt, from june to july 1846, a small group of american settlers in california rebelled against the mexican government and proclaimed california an independent republic. the republic was short-lived because soon after the bear flag was raised, the u.s. military began occupying california, which went on to join the union in 1850. the bear flag became the official state flag in 1911.

civil disobedience, refusal to obey the demands or commands of a government or occupying power, without resorting to violence or active measures of opposition