Question

an individual was exposed to a contagious disease but did not become infected. the agent was unable to enter the body and grow because it was stopped by the persons skin. this is an example of how a ______ can prevent disease. a. chemical barrier b. physical barrier c. protective behavior d. medication

Explanation:

The skin is a physical structure that physically blocks the entry of the disease - causing agent. A chemical barrier would involve substances like enzymes or acids (not just the physical presence of skin). Protective behavior would involve actions like avoiding contact (not the inherent physical property of skin). Medication is an external substance taken (not related to the skin's physical structure here).

Answer:

B. physical barrier