CaCl2 is preferred over NaCl for clearing ice on roads particularly in very cold countries. This is because :
a. CaCl2 is less soluble in H2O than NaCl
b. CaCl2 is hygroscopic but NaCl is not
c. Eutectic mixture of CaCl2/H2O freezes at −55∘C while that of NaCl/H2O freezes at −18∘C
d. NaCl makes the road slippery but CaCl2 does not