An Insectivorous Bird Has the Choice of Eating (1)meadow Beetles,which

An insectivorous bird has the choice of eating (1) meadow beetles,which are abundant and large but expose the bird to hawk predation; (2) under- a- rock beetles,which are large and fatty but hard to obtain; and (3) under- a- leaf beetles,which are easy to obtain but small.The bird has nestlings to feed.As an optimal forager,it will

A) concentrate on under- a- leaf beetles because they are easy and safe.
B) eat all three kinds of beetles,balancing the energy spent and the risks incurred against the energy gained.
C) eat one kind of beetle at a time (first under- a- leaf,then meadow,then under- a- rock) ,switching to a new kind when the old kind becomes scarce.
D) concentrate on under- a- rock beetles because they are energy- rich.