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.

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!