The Base-Dissociation Constant of Ethylamine (C₂H₅NH₂)is 6

The base-dissociation constant of ethylamine (C₂H₅NH₂) is 6.4 × 10^-4 at 25.0 °C. The [H⁺] in a 1.6 × 10^-2 M solution of ethylamine is __________ M.

A) 3.5 × 10^-12
B) 2.9 × 10^-3
C) 3.1 × 10^-12
D) 3.2 × 10^-3
E) 11.46