Which Example Is a Mutualistic Interaction

Which example is a mutualistic interaction?

A) Barnacles obtain safe haven by riding on a whale,while the whale is unaffected.
B) A bacterial species lives inside a plant's roots and provides usable nitrogen to the plant,which in turn provides sugar nutrients to the bacteria.
C) A virus infects a bird,thus reducing the bird's fecundity.
D) A wasp lays its egg inside a caterpillar,and the hatched wasp larva consumes the caterpillar.
E) A bluejay forces sparrows to leave a bird feeder so that it can eat the seeds.