Four pairs of words are given out of which the words in three pairs are related in some way and words in one pair are different. Find out that pair which is differently related.

The answer is D. Criminals and Prison.

In the other three pairs, the first word is a living thing and the second word is a place where that living thing lives. For example, fish live in aquariums, birds live in nests, and students learn from teachers. However, criminals do not live in prisons. Prisons are places where criminals are kept after they have been convicted of a crime.

Here is a more detailed explanation of each pair:

• Fish and Aquarium: Fish are aquatic animals that live in water. Aquariums are artificial habitats that are designed to house fish.
• Bird and Nest: Birds are avian animals that lay eggs and build nests to incubate their eggs and raise their young.
• Student and Teacher: Students are people who are learning, and teachers are people who teach.
• Criminal and Prison: Criminals are people who have been convicted of a crime, and prisons are places where criminals are kept.

I hope this explanation is helpful!