With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: After the Spanish invasion and colonisation of the Inca Empire, the use of coca was restricted and appropriated by the Spaniards. By many historical accounts, the Spaniards tried to eradicate the coca leaf from Inca life. The Spaniards enslaved Inca people and tried to take "the luxury" of the coca leaf away from them. Although the Spaniards noticed the state-controlled storage facilities that the Inca had built to distribute to its workers, they were still ignorant to the importance of this divine plant for Inca people. Not only that, enslaved Inca people were not capable of enduring the arduous labour the Spaniards made them do without using coca. Even though Spaniards were trying to push catholicism onto the Inca, which did not allow them to eat before the Eucharist (the Spaniards thought coca to be food), they allowed them to continue to use coca to endure the labour associated with slavery. After seeing the effects and powers of the coca plant, many Spaniards saw another opportunity for appropriation of Inca culture and started growing and selling coca themselves.
text_B: Where the Inca people subject to slavery under the rule of Spain?
YES.