The State of Missoula has enacted a new election code designed to increase voter responsibility in the exercise of the franchise and to enlarge citizen participation in the electoral process. None of its provisions conflicts with federal statutes. Which of the following is the strongest reason for finding unconstitutional a requirement in the Missoula election code that each voter must be literate in English?

A. The requirement violates Article I Section 2 of the Constitution, which provides that representatives to Congress be chosen "by the People of the several States."
B. The requirement violates Article I, Section 4 of the Constitution, which gives Congress the power to "make or alter" state regulations providing for the "Times" and "Manner" of holding elections for senators and representatives.
C. The requirement violates the due process clause of the Fourteenth Amendment.
D. The requirement violates the equal protection of the laws clause of the Fourteenth Amendment