Which of the following best describes the process of gas exchange in insects?
A. Oxygen is carried directly to the cells through a tracheal system.
B. Gas exchange is done using the cerebral ganglion.
C. Insects have lungs that function similar to every other arthropod.
D. Insects have book lungs, which are like stacks of tissue and gas pockets.
E. Gas exchange is done by diffusing air through the exoskeleton.