Question

review the details below.
chameleons may change colors to express emotional states, such as fear, anger, and surprise.
while chameleons are usually brown or green, they may turn darker or lighter to warm up or cool off.
male chameleons display bright colors to signal that they are ready to mate.
choose the best topic sentence to introduce a paragraph containing these details.
chameleons are able to change colors due to a specialized process that affects pigments below a transparent layer of skin.
chameleons can show a wide range of colors, from bright to muted.
chameleons change color as a response to varying emotional and physical states.

Explanation:

The details mention color - changing in response to emotions (fear, anger, surprise) and physical states (warming up, cooling off, mating readiness). The third option encompasses these aspects as it refers to both emotional and physical states for color - changing. The first option focuses on the process of color - change rather than the reasons, and the second option just states the range of colors without the reasons for color - change.

Answer:

Chameleons change color as a response to varying emotional and physical states.