In john c. calhoun's eyes, what made slavery "a positive good"? (5 points)
a. it led to more rapid economic and industrial development than was possible in the regions without it.
b. slaves who ran away to the north suffered great hardships that led many to return to their former masters.
c. it contributed to the strength of the union because it caused regions to depend so clearly on each other.
d. slaves had a better quality of life than wage workers in factories, who had no health care or other protections.