Q: Fact 1: Freezing causes a solid to form. Fact 2: Freezing is a physical change. Given the two facts above, what causes solids to form?

Select from:
a). Physical weathering;
b). an external framework;
c). Physical changes;
d). adding sand;
e). adding mud;
f). heating liquids;
g). adding water;
h). A solid geometric shape;
The answer is:
c).