Which of the following groups of people would be the least affected by air pollution?
a. people with asthma
b. infants
c. teenagers
d. the elderly

The group which would be the least affected by air pollution are C. teenagers. This is because their respiratory systems have already been established and are quite strong because they are still young and healthy. People with asthma already have troubles breathing, so obviously air pollution is going to be a problem. Infants are still too young to have complete respiratory systems, so they would be affected by this, as well as the elderly, whose breathing systems are starting to fail due to their age.