In which solution will 0.010M Ca^2remain soluble?

In which solution will 0.010M Ca^2 remain soluble?
a. 5.0×10^-7 M CO3^-2; Ksp of CaCO3=4.5×10^-9
b. 6.0×10^-5 M F; Ksp of CaF2= 3.9×10^-11
c. 0.030M OH; Ksp= Ca(OH)2= 6.5×10^-6
d. 5.0×10^-12; Ksp= Ca3(PO4)2= 2.0×10^-29