This question has two parts. First, Answer Part 1. Then answer Part 2.
A student makes a terrarium, containing plants and a lizard. Lizards are cold-blooded animals, which means that their body temperature varies with the temperature of the environment. Because of this, they cannot live in an extremely hot or cold environment. The student places the terrarium on a windowsill so that the sun will shine on the lizard.
Which of these could the student use with the terrarium that would help the lizard survive at night?