What Is the Zero-One Rule

What is the zero-one rule?

A) A prediction of the optimal diet model that says that a food type is either always eaten or always rejected
B) A prediction of the optimal patch model that says that a patch should either be completely exploited or ignored
C) A prediction of OFT models that says that GUDs should always be zero or one
D) An assumption of the optimal diet model that says that diminishing returns begin at one and decline to zero
E) An assumption of OFT models that says that energy intake rate is either zero or one