Cynthia lives in Miami, a city at low altitude. She goes on a month-long trip to the Andes Mountain range (at high altitude) where the air pressure is lower and therefore there is less oxygen in each breath she takes. Upon returning to Miami, how might a sample of her blood differ from a sample taken before she left for her trip?

• A. Each of her blood cells would carry fewer hemoglobin molecules.
• B. Each of her hemoglobin molecules would carry 5-6 oxygen molecules.
• C. Her hematocrit will have increased (more erythrocytes per μL).
• D. There would likely be no change.