Which of the Following Exemplifies Mutualism

Which of the following exemplifies mutualism?

A) Lima beans produce volatiles that attract carnivorous mites only when the plants are being damaged by a spider mite.
B) The bullhorn acacia tree provides a home and food for ants that in turn protect the plant from herbivores.
C) After a leaf is chewed or injured,a plant produces proteinase inhibitors.
D) A plant with a viral infection initiates a hypersensitive response (HR) that seals off the infected area.
E) Because the leaves of some passion flowers display physical structures resembling the yellow eggs of Heliconius butterflies,these butterflies do not lay eggs on this plant.