Phosphoric Acid Is a Triprotic Acid in Water,ionizing in the Following

Phosphoric acid is a triprotic acid in water,ionizing in the following sequential steps: H₃PO₄ + H₂O $\leftrightarrows$ F10 H₂PO₄^- + H₃O⁺ = 7.11 *10^-3
H₂PO₄^- + H₂O $\leftrightarrows$ HPO₄^2- + H₃O⁺
= 6.32 *10^-8
HPO₄^2- + H₂O $\leftrightarrows$ PO₄^3- + H₃O⁺
= 4.5 *10 ^{- 13}
What is the pH of a 0.20 M H₃PO₄ solution?

A) 2.84
B) 1.46
C) 2.15
D) 4.09
E) 5.37