Communicable diseases are characterized by being infectious and transmissible between individuals. Which statement best reflects this characterization?

• A. Infectious and transmissible
• B. Noninfectious and nontransmissible
• C. Infectious but not transmissible
• D. Noninfectious and transmissible

Answer: (A)

The main idea is that communicable diseases require a pathogen that can be spread from one person to another. Infectious means the disease is caused by a pathogenic agent, while transmissible means there is a way for that agent to move from one person to another (through contact, droplets, air, vectors, etc.). So the statement that captures both features—being infectious and transmissible—best reflects the concept. The other descriptions don’t fit: diseases that are noninfectious aren’t caused by pathogens, and nontransmissible diseases don’t spread between people, which would not be considered communicable.