What Is the PH of a Solution Prepared by Mixing $\times$

What is the pH of a solution prepared by mixing 450 mL of 1.2 M HF with 590 mL of 0.98 M NaF? The K_a of hydrofluoric acid is 6.8 $\times$ 10^-4.Assume volumes are additive.

A) 3.17
B) 3.08
C) 3.14
D) 3.20
E) 3.26