What Is the Molar Solubility of PbF₂ in a Buffer

What is the molar solubility of PbF₂ in a buffer solution in which the [H⁺] concentration is roughly constant at 0.080 M? (K_sp of PbF₂ is 3.2 *10^-8; K_a of HF =6.8 * 10^-4.)

A) 1.1 * 10^-4
B) 3.2 *10^-
C) 7.4 * 10^-3
D) 8.4* 10^-3
E) 4.8 * 10^-2