Calculate the pH of a 0.650 mol/L phosphoric acid solution. Also, determine the equilibrium concentrations of H3PO4, H2PO4⁻¹, and HPO4⁻². Ka1 = 7.1 x 10⁻³, Ka2 = 6.3 x 10⁻⁸, Ka3 = 4.2 x 10⁻¹³

a. 2.14
b. 3.67
c. 4.92
d. 5.78