How Many Mmoles of HCl Must Be Added to 130

Multiple Choice

How many mmoles of HCl must be added to 130.0 mL of a 0.40 M solution of methylamine (pK_b = 3.36) to give a buffer having a pH of 11.59?

A) 16 mmol
B) 0.11 mmol
C) 5.2 mmol
D) 2.5 mmol
E) 0.91 mmol