Which of the following best describes what alveoli are? a. they are the smallest tubes in the respiratory system. b. they have a small amount of surface area. c. they are found on the end of bronchioles. d. they are comprised of millions of cells. select the best answer from the choices provided.

Alveoli small balloon-like structures which are responsible for the oxygen exchange in the lungs  across the membranes. These are attached to the branches of the bronchial passages. These alveoli inflate and deflate with inhalation and exhalation. Answer is C.

ANSWER: C. They are found on the end of bronchioles.

HOPE THIS HELPS

70 % i think is the answer.