Who was largely responsible for the new burst of expansion in continental europe in the second century c. e.?

What was the main argument of plessy in plessy v. ferguson

The factory system of the early-19th century caused a) a decrease in farm production. b) an increase in rural population. c) an increase in urban population. d) high unemployment in other areas.

Which events are correlated but do not necessarily have a causal relationship?