Which of the following is a disease that has been completely eradicated?

Correct option is C

Ans. (c) Smallpox
Sol. Smallpox is the only human disease that has been completely eradicated globally, officially declared by the WHO in 1980.
Explanation of each option:
· (a) Cholera – Still exists in many parts of the world.
· (b) Plague – Still reported occasionally in some countries.
· (c) Smallpox – Correct. Successfully eradicated through global vaccination programs.
· (d) Polio – Eradicated in some regions but still exists in a few countries.