Which of the following signals would be LEAST likely to be regarded as a necessarily honest signal of the sender's quality?

A) a male blue gourami spreading his fins when his territory is invaded.
B) a male blue-footed booby displaying his bright blue-green feet to a female.
C) a male common loon's "yodel" call when a rival male encroaches on his territory.
D) a male red deer's constant roaring during the rut.