Final answer:
The property that is not a colligative property of a salt solution is the lower density of ice than the solution from which it forms.
Step-by-step explanation:
The property that is not a colligative property of a salt solution is E. The lower density of ice than the solution from which it forms. Colligative properties depend on the number of solute particles, not their chemical identity. The other options, A. Lowering of vapor pressure with increasing concentration, B. Elevation of the boiling point with increasing concentration, C. Depression of freezing point with increasing concentration, and D. Osmotic pressure increases with increasing concentration, are all examples of colligative properties.