Which of the following is a physiological adaptation?
a. group hunting
b. hyoid bone adapted for roaring
c. dark coloration
d. migration

The right option is b. hyoid bone adapted for roaring

A physiological adaptation is the adjustment and the regulation of an organism’s internal body functions in order to cope with its changing environment. A physiological adaptation is also an organism’s response to a certain external stimulus in order to maintain homeostasis. Hyoid bone adapted for roaring and the production of venom by snakes to avoid predators are examples of physiological adaptation.

idk about that one.