Why Is Calcium Chloride, , More Effective at Melting

Why is calcium chloride, , more effective at melting ice than sodium chloride, NaCl?

A) Calcium ions are both larger and more highly charged and thus more effective in breaking the ice crystal structure.
B) Calcium ions are smaller than sodium ions and thus more able to get in the way of the water molecules attempting to form the solid state lattice.
C) Calcium chloride produces three ion particles while sodium chloride produces only two. Greater numbers of ions are more effective at decreasing the number of water molecules entering the solid phase.
D) Sodium ion is a natural water softener and therefore not as effective in inhibiting the formation of the solid state of water from the liquid.