The Respiratory System of Insects Consists of

The respiratory system of insects consists of

A) branched air tubes called spiracles that supply blood capillaries.
B) branched air tubes called tracheae and tracheoles that end in air capillaries.
C) branching gill systems that end in openings called tracheae.
D) branching gill systems that end in openings called tracheoles.
E) extensive layers of gas exchange tissue just under the exoskeleton.