John Endler's (1978) Definition of an Animal's Ability to Match

John Endler's (1978) definition of an animal's ability to match background color as resulting from the animal's resemblance to a random sample of the visual background provides us with

A) a way to quantify the similarity between prey coloration and its background.
B) the answer to questions regarding the function of the coloration.
C) the most successful definition yet suggested.
D) all of the above.