i feel like none of these answers are right.
if the solubility of the solid is 'S' mol/ L, what is the Ksp of the product of the salt?
Ca3PO42-(s) --> 3Ca2+(aq) + 2PO42- (aq)
Only leaning towards D because its the only one that makes sense...
See my response to your post above.posted by DrBob222