Final answer:
Black sharecroppers under the system of sharecropping were forced to pay for land and supplies by giving a share of the crops they grew to their landlords, often trapping them in cycles of debt and economic injustices.
Step-by-step explanation:
Under the system of sharecropping, black sharecroppers were tenant farmers who paid for the use of land and supplies by giving a portion of the crops they grew to their landlords. They often entered into arrangements where they worked on the same plantations where they had previously been enslaved. Due to the crop lien system and high-interest rates, sharecroppers found themselves in cycles of debt that inhibited their ability to become landowners or establish independent livelihoods, leading to significant economic injustices.
The correct answer to the provided question is: b. were forced to pay for land and supplies by giving a share of the crops they grew to their landlords.