Answer:
A. Arbitrariness.
Explanation:
When Western Fence Lizards express territorial claims, their bellies turn blue. This illustrates the design feature arbitrariness.
Arbitrariness is the characteristic of being "by circumstance, instinct, or inclination decided and not by need, intention, or theory." It is often used to refer to a decision taken with little or no specific requirements or constraints. Arbitrary choices are not necessarily the same as those taken at random.
