Which Statement Explains Why Ice Floats in Liquid Water

Which statement explains why ice floats in liquid water?

A) As water molecules go from the liquid to the solid state, their rate of motion decreases.
B) Water molecules maintain the same bent shape in liquid and solid states.
C) The ordered lattice structure of water molecules in ice is maintained by hydrogen bonds.
D) The arrangement of water molecules in ice results in fewer molecules per unit volume than in liquid water.
E) Water molecules maintain the same mass as they transition from the liquid to the solid state.