The correct answers are
b. were never involved in agriculture but only in manufacturing enterprises.
c. made up well over half the population of the empire.
and
e. staged a number of massive rebellions, the largest led by Spartacus in 71
Their slavery system was different than that in newer times because for them anyone could be a slave. They would enslave people regardless of race, gender, nationality, class, or similar. If you committed a crime or were in debt or were conquered, you could become a slave.
