According to the Fifteenth Amendment, citizens should not be denied the right to vote based on race or previous enslavement. Despite this federal mandate, Southern states enacted laws to prevent African Americans from voting. Initially, they imposed poll taxes and literacy tests as voting prerequisites. Subsequently, states introduced "grandfather clauses." These provisions allowed individuals to vote without passing the literacy test or paying the poll tax if they, their fathers, or grandfathers had been eligible to vote on or before January 1, 1867. Why were grandfather clauses enacted? A. Southerners recognized the unfairness of literacy tests and poll taxes for the impoverished. B. African Americans pushed for grandfather clauses. C. Literacy tests and poll taxes had disenfranchised white voters. D. Grandfather clauses offered a fair method for determining voting eligibility.