It's considered to be an advantage to have lungs with increased capacity, because with increased capacity
a. anaerobic exercise is easier.
b. the lungs will fight off colds and influenza.
c. the chest looks more "buff."
d. the lungs can better exchange oxygen and waste products in the blood.

Having more lung capacity is advantageous because the lungs can expand more. More air in the lungs will fill all the alveoli (air sacs in the lungs) and allow more oxygen to enter the bloodstream via the capillaries that surround the air sacs. Excess waste (such as carbon dioxide) is also transferred from the blood to the air to be exhaled. As lungs fill, more gas exchange can occur.

Hope the answer is b