Hydroazoic acid (HN₃) has a Ka of 1.9 × 10⁻⁵.
a) Calculate the percent ionization of HN₃ in an aqueous solution that is 0.400 M HN₃.
b) Without doing any calculations, determine if the solution of hydroazoic acid (HN₃) with a concentration of 0.400 M is best described as:

A) A solution of a strong acid
B) A solution of a weak acid
C) A neutral solution
D) A basic solution