Herring occur in large schools (or patches) off the coast of Norway, which are searched for and fed upon by killer whales

Herring occur in large schools (or patches) off the coast of Norway, which are searched for and fed upon by killer whales. Once a school of herring is discovered by a foraging whale, it consumes the fish, eventually reducing their density to such a level that the whale moves on in search of another school of herring. The decision by a whale of when to abandon a school of anchovies and look for another is done in such a manner as to maximize the long-term rate of food intake, which in turn is predicted by the marginal value theorem.

(a) Define the the marginal value theorem, including its main underlying assumption.

(b) Then, describe the two factors that influence the whale's leaving time.

(c) Finally, describe how the marginal value theorem can be used to predict how long a whale should remain in a school of anchovies, or in other words, at what point the whale should decided to leave a school of anchovies