Read these sentences from the text. Alex is not a smoker, but he lives near St. Louis, named the worst place in the U. S. for asthma sufferers by the Asthma and Allergy Foundation of America in 2009. The group rated St. Louis low for having poor air quality and because it doesn’t have as many laws as other places keeping indoor areas smoke free.

Based on this evidence, what can you conclude about asthma sufferers in St. Louis?
A. St. Louis is the only city in the United States where asthma is common.
B. Poor air quality and indoor smoking can cause problems for asthma sufferers.
C. Poor air quality and indoor smoking have no effect on asthma sufferers.
D. There are more asthma sufferers in St. Louis than any other city in America.