Three of the following four are alike in a certain way and one is different. Choose the odd one out.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Kala-azar
Group the diseases by the kind of germ that causes them.
Option (1) Measles — caused by a virus.
Option (2) Kala-azar — caused by a protozoan (Leishmania), spread by the sandfly.
Option (3) Rabies — caused by a virus, spread by the bite of an infected animal.
Option (4) Mumps — caused by a virus; it makes the glands near the jaw swell.
Measles, rabies and mumps are viral diseases; kala-azar is caused by a protozoan, so Kala-azar is the odd one out.