Which Is Evidence That an Organ System Provides a Level

Multiple Choice

Which is evidence that an organ system provides a level of function not possible with individual organs operating independently?

A) Bears grow thick fur on their bodies.
B) Blood circulates to all tissues of a horse's body.
C) Humans produce antibodies that bind to invading pathogens.
D) Bones in mammals are composed of living cells.
E) The dog stomach produces digestive enzymes.