In which of the following solution the depression in freezing point is lowest?
A. 0.2 M urea and 0.2 M glucose
B. 0.1MAl2(SO4)3and0.1MNa2SO4
C. 0.1MKNO3and0.2MBa(NO3)2
D. 0.1MCa(NO3)2and0.1MBa(NO3)2