The Respiratory System of Insects Consists of

The respiratory system of insects consists of

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