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As each compound is made of one anion and one cation therefore the molar solubility can be found out by taking the squar root of the colubility product.

Dissociation of each can be written as

BaCrO4-------Ba2+ +CrO4^2-

PbS--------->Pb2+ +S2-

BaSO4 -------->Ba2+ +SO4^2-

SrCO3--------->Sr2+ + CO3^2-

Let the molar solubiltiy of each salt be x.

Then Ksp =x*x

x=sqrt(Ksp)

By taking the square root of each ,we find the largest solubility to be of SrCO3.

Molar solubility=sqrt(9.3*10^-10) =3.05*10^-5

answer-option D

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