Detailed Instructions: 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).
Problem:Paragraph: Smoking reduces the amount of oxygen available for diffusion at the lungs, so less oxygen gets absorbed and blood is oxygenated to a lesser degree.
 Question: Suppose that Mary smokes cigarettes for 20 years. If you measured the oxygen levels in her blood before she started smoking and compared them to oxygen levels later in her life, what would you find? 
 Choices: A)less oxygen in her blood later in life 
B)more oxygen in her blood later in life
Solution:
less oxygen in her blood later in life