To benefit from a cheaper labor pool, some businesses in the 1950s began to
a. hire african americans.
c. expand overseas.
b. hire teenagers.
d. move to the sunbelt.

To benefit from a cheaper labor pool, some businesses in the 1950s began to expand overseas - c.

This enabled these companies to pay the workers less and for that reason they were able to lower their prices substantially; or rather lower the costs and keep the prices the same. 

The Arkansas river carries most of Oklahoma's runoff water.