The K_sp of CaF₂ Is 4 * 10^-11

The K_sp of CaF₂ is 4 * 10^-11. What is the maximum concentration of Ca²⁺ possible in a 0.10 M NaF solution

A) 4 * 10^-7 M
B) 4 * 10^{- 8} M
C) 4 * 10^-9 M
D) 4 * 10^-10 M
E) None of the above