According to Martha Olney Why Did Blacks Buy on Installment

According to Martha Olney why did blacks buy on installment at almost twice the rate of whites?

A) Installment contracts were formal and could be used legally for repossession while credit agreements could not.
B) Blacks did not like to buy things on credit.
C) Blacks were more likely than whites to purchase goods that required installment purchases.
D) It was easier for blacks, who tended to have lower income than whites, to pay off their debts on a regular schedule that the installment plans offered.