Which describes the Tokugawa shogunate?
a. a dynasty created after Ieyasu defeated rival warlords and united Japan under one rule that closed Japan's borders to foreign trade in order to limit western influence
b. a dynasty created after Ieyasu defeated rival warlords and united Japan under one rule that increased trade and cultural exchange with foreign nations
c. a dynasty that restricted trade with foreign nations to boost the economy, established Buddhism as the state religion, and created national unity
d. a dynasty created when the shogun defeated Ku