The CDC (Center for Disease Control) hires many people with science degrees. What may be one of the responsibilities of someone who works there?
A) Use advanced laboratory instruments to study how the body digests food.
B) Monitor what substances are produced and sold on the illegal drug market.
C) Checking the safety levels of hazardous substances at nuclear power plants.
D) Tracking different strains of influenza (flu) as they spread throughout the United States.