What Is the PH of Water, If Its [ $\mathrm { H } _ { 3 } \mathrm { O } ^ { + }$

What is the pH of water, if its [ $\mathrm { H } _ { 3 } \mathrm { O } ^ { + }$ ] concentration is 3.00 × $10 ^ { - 3 }$ ?

A) 4.07
B) 7.04
C) 5.53
D) 2.52
E) 3.01