You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).

Let me give you an example: Paragraph: Many of the worlds people live with water scarcity, and that percentage will increase as populations increase and climate changes.
 Question: John's town used to have lots of water, back when there were only a few hundred people. However, now that the town holds several thousand people, the water availability is 
 Choices: A)scarce 
B)plentiful
The answer to this example can be: scarce
Here is why: Based on the information given in the paragraph, population growth will make water more scarce, so that is the correct answer.

OK. solve this:
Paragraph: More pollutants mean poorer air quality.
 Question: Michael is studying the air quality of various cities. He finds that there are many more pollutants in the air in Mexico City, than there are in the air of Chicago. Therefore, the air quality will be lower in 
 Choices: A)Chicago 
B)Mexico City
Answer:
Mexico City