Explanation:

To find the correct word for the given group of words we need to check the meaning of all the words given as options.

1. concoction - a mixture of various ingredients or elements.

2. conflagration - an extensive fire which destroys a great deal of land or property.

3. confederation - an organization which consists of a number of parties or groups united in an alliance or league.

4. constellation - a group of stars forming a recognizable pattern that is traditionally named after its apparent form or identified with a mythological figure.

Hence option 4 is the correct answer costellation is the most suitable word for defining the group of words.