You Wish to Deice Your Driveway,so You Consider Buying 10

You wish to deice your driveway,so you consider buying 10 lb of NaCl,10 lb of CaCl₂,or 10 lb of MgCl₂.Which of these would deice your driveway most effectively? Assume that ideal dissociation of the salts occurs and that colligative properties are the only consideration.

A) 10 lb NaCl will deice best.
B) 10 lb CaCl₂ will deice best.
C) 10 lb MgCl₂ will deice best.
D) The three driveways will deice to the same extent.
E) 10 lb of CaCl₂ or 10 lb of MgCl₂ will deice equally well.