Click, Clack, and Jim Have Identical Icy Driveways

Multiple Choice

Click, Clack, and Jim have identical icy driveways. Click buys 10 lb of NaCl, Clack buys 10 lb of CaCl₂, and Jim buys 10 lb of MgCl₂. They spread these salts on their driveways. Which driveway will deice more effectively? (Assume that ideal dissociation of the salts occurs, and that colligative properties are the only consideration.)

A) Click's driveway will deice best.
B) Clack's driveway will deice best.
C) Jim's driveway will deice best.
D) The three driveways will deice to the same extent.
E) Clack and Jim's driveways will deice better than Click's.