Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Two students make hot chocolate. One student pours the hot chocolate into a foam cup. The other student pours the hot chocolate into a metal cup. The metal cup becomes too hot to touch, but the foam cup can be held comfortably. The best explanation for this difference in temperature is that the foam cup-- A heats up much faster than the metal cup
is a better conductor of heat than the metal cup
The foam cup insulates better.