80 kg of Na2SO4 (molecular weight = 142) is present in 330 kg of an aqueous solution. The solution is cooled such that. 80 kg of Na2SO4 .10H2O crystals separate out. The weight fraction of Na2SO4 in the remaining solution is_________________?
A. 0.00
B. 0.18
C. 0.24
D. 1.00