If thermoregulation is considered to be a secondary function of the large ears of jackrabbits, then the primary function of the ears is
A) to optimize nutrient intake through the thin, permeable surfaces on the ears.
B) to alter the rate of gas exchange, based on the adjustable radius of the ears' blood vessels.
C) to detect predators by using the large size and flexible positioning of the external ears to channel sound waves into the ear canal.
D) to protect offspring from bright sunlight by the positioning of the ears to cast the maximum shadows.
E) to protect against pathogens by having a thick, waxy surface on the ears.
Answer: C