Tiny air sacs in the lungs are destroyed, making breathing extremely difficult, is the disease called O emphysema
chronic bronchitis
O coronary heart disease
o lung cancer

the answer to your question is:

c. complementary base-pairing

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.