What Is the PH of an Aqueous Solution That Contains

What is the pH of an aqueous solution that contains 0.085 M HNO₂ and 0.10 M potassium nitrite (KNO₂) ?
K _a(HNO₂) = 4.5×10 ^{- 4}

A) pH = 3.27
B) pH = 3.42
C) pH = 4.28
D) pH = 4.42
E) pH = 7.87