Which scenario describes a relationship of mutualism? Oxpecker birds eat parasitic ticks off the backs of zebras.

A tapeworm latches itself in the intestines of a rat, feeding off all the nutrients eaten by the rat.

Birds feed off the insects that are stirred up from the grasses as cattle move through.

A polar bear catches a seal for dinner.

Two technicians are discussing oil changes. technician a says that waste oil and old filters need to be disposed of according to the law. technician b says that old filters can be returned to the parts department for a core value. which technician is correct?           a. technician a only   b. both technicians a and b   c. technician b only   d. neither technician a nor b