Q: Fact 1: Insulated material can be used for keeping warm. Fact 2: Insulators are materials that prevent the flow of heat. Given the two facts above, materials that prevent the flow of heat can be used for keeping what?

Options:
a). airy;
b). power;
c). warm;
d). liquid;
e). dry;
f). energy;
g). empty;
h). down;
The answer is:
c).