Answer:
C. Slaves worked in various position in society, spread out rather than concentrated in large, hard labor groups.
Explanation:
In ancient Greece, slaves were not a product of race. People became slaves because they lost a war. Also, people who were taken as war criminals, immigrants ended in slave market.
In ancient Greece, families abandoned their children either because they cannot take care of them or do not want them, which is somewhat similar to todays' "abortion". These children are then rescued by another family and then raised as slaves.
Unlike models of slavery in later societies, slaves in ancient Greece were not exploited because they were poor, uncivilised or infererior. Though, they were not allowed to engage in politics but were mostly found in other areas.
Some of these slaves think for themselves and possess intelligence. Positions as tutors, secretaries were held by them. Owning an intelligent and educated slaves was precious then.
Summarily, slaves worked in various positions in society, spread out rather than concentrated in large, hard labor.