​Which of the following diseases is caused by bacteria?​

Correct option is A

The correct answer is (A) Diphtheria.​

• Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae.
• It affects the mucous membranes of the throat and nose, leading to symptoms like a sore throat, fever, and a thick coating in the throat, which can make breathing difficult.

• Measles: Caused by a virus, specifically the measles virus.
• Mumps: Caused by a virus, specifically the mumps virus.
• Chicken Pox: Caused by the varicella-zoster virus, not bacteria.