Which economic mechanism does a barter system operate without? a. opportunity costs b. money c. supply and demand d. goods and services

Pls me! the black codes were various state laws in the south concerning african-americans which of the following statements about the black codes is not accurate. a. the black codes protected the civil rights of african-americans. b. african americans who cannot afford to pay a fine could be jailed and then be hired out to anyway person who could pay the fine. c. some southern states passed laws that prohibited is african-americans from voting or serving on jury‘s. d. the black codes were designed to force african-americans into a condition of near slavery.