It was located in africa. hope this helps <3
Because of the options you give, I know that we did the same test. Anyway, the Crimean war wasn't a major cause but because of Autocratic rule. I am 80% sure its that one, since they've had a history in that stuff.
The main reason why slavery spread was that people owned large pieces of lands and they needed cheap work force. What better for them than to have a work force that was strong and completely free.
