Question

which is the best way to complete the text? while it is true that some species of chameleons have the ability to change their skin color. they really use this attribute to regulate their body temperature - not to hide detection.

Explanation:

In English grammar, a new sentence should start with a capital - letter. The first word after the period in the given text should be "They" with a capital 'T'. Also, a comma is needed after "color" to separate the introductory clause from the main clause.

Answer:

color, They