Answer: hepatitis C.
Step-by-step explanation:
Based on the information given in the question, it's most likely that the person has been exposed to hepatitis C.
Hepatitis C is an infection that is caused when a virus attacks the liver which leads to the inflammation of the liver. Since the person reaches the scene of a car accident, it's possible that the EMT got in contact with the contaminated blood. In this case, he most likely have been exposed to hepatitis C.