Which of the following is equal to the solubility of Ba(IO3)2, a poorly soluble salt, in water? Ksp=1.57×10^-9

a) 1.98×10^-9M
b) 2.80×10^-5M
c) 7.32×10^-4M
d) 1.98×10^-5M
e) 7.32×10-3M

..................... Ba(IO3)2 --> Ba^2+ + 2IO3^-..............Ksp = 1.57E-9

I.......................solid..............0............0
C......................-x..................x............2x
E......................solid...............x............2x
Ksp = (Ba^2+)(IO3^-)^2 = 1.57E-9
Substitute the E line into the Ksp expression above and solve for x = solubility