The correct option is D (Ksp27)14
For the salt AxBy
AxBy=xAy++yBx− s 0 0 − xs ys
the solubility of a sparingly soluble salt is given by Ksp=(xs)x.(ys)y,
In the given salt AB3
x=1 and y=3
Ksp=(1s)1.(3s)3,, by rearranging,we get solubility denoted by s as (Ksp27)14