Which of the following statements accurately describes European pressure on China in the 1800s?

a. Despite its weakness in the later 1800s, China was able to avoid allowing European powers special 'spheres of influence' where they might have military bases, mine, and construct railroads.
b. Following military defeats at the hands of the British and French, the Chinese had to allow foreigners freedom to travel and trade within China, to engage in missionary work, and even to patrol Chinese rivers.
c. The 'Opium Wars' were trade embargoes on Chinese goods imposed by the British in an attempt to stop the export of that addictive drug to Britain.