The H₃O⁺ Concentration of a Solution Is 2 $\times$ 10^-6 M

The H₃O⁺ concentration of a solution is 2.5 $\times$ 10^-6 M.What is the pH of the solution?

A) 6.81
B) 3.77
C) 2.00
D) 5.60
E) 10.60