Here are the answers to the given questions above:
1. Compared to adults,a newborn breathes a quarter as often. The answer is option A. A newborn breathes 30 to 60 times per minute and an adult breathes 12 to 20 breathes per minute.
2. The cluster of air sacs at the end of each bronchiole is called Alveoli. The answer is option C.
3. The flap of elastic cartilage that protect food from entering the larynx is called the epiglottis. The answer is option A.
4. When blood leaves the lungs it is, oxygenated. The answer is option A.