Which statement best describes chronic diseases in relation to infectious diseases?

• A. Chronic diseases are short duration and contagious.
• B. Chronic diseases are irreversible in all cases.
• C. Chronic diseases are long duration and not contagious.
• D. Infectious diseases are self-limiting acute illness.

Answer: (C)

The key idea here is how chronic (non-communicable) diseases behave compared to infectious diseases. Chronic diseases are long-lasting conditions that persist for many years, often a lifetime, and they are not spread from person to person. That combination—long duration and non-contagious transmission—defines them in relation to infectious diseases, which are caused by pathogens and can be contagious, often acting over shorter time frames.

So the statement that best fits is that chronic diseases are long in duration and not contagious. The other descriptions mix up duration, contagion, or the typical course of infectious diseases, which makes them less accurate overall.