Which of the following best describes the process of gas exchange in insects?

Choose best answer below:

1. oxygen is carried directly through a tracheal system.
2. gas exchange is done by diffusing air through the exoskeleton.
3. insects have lungs that function similar to every other arthropod.
4. gas exchange is done using the cerebral ganglion.
5. insects have book lungs which are like stacks of tissues and gas pockets.