What Is the Minimum Concentration of CN^-(aq)that Will Prevent the Precipitation

Multiple Choice

What is the minimum concentration of CN^-(aq) that will prevent the precipitation of AgX(s) from a solution that is 0.149 M in X^-(aq) and 0.0184 M in Ag⁺(aq) ?
(K_sp for AgX(s) = 5.2 × 10^-17;K_f for Ag(CN) ₂^- = 5.6 × 10¹⁸)

A) 3.1 × 10^-3 M
B) 9.4 × 10^-6 M
C) 1.8 × 10^-10 M
D) 1.2 × 10^-3 M
E) 9.6 × 10^-3 M