Correct Answer: (Stock, Troupe, Robber)

Solution : Let's check the options –
First option: (Stock, Troupe, Robber); In this set, stock and troupe are terms used to represent groups or collections of entities. Stock refers to a group of animals, particularly domestic livestock. On the other hand, a troupe is used for a group of performers or actors. However, a robber is an individual who does not fit into the pattern of representing a collective group.
Second option: (Crowd, Army, Herd); In this group, all the words represent collective groups. Crowd refers to a gathering of people, army signifies a group of soldiers, and herd denotes a group of animals, typically cattle or similar animals.
Third option: (Team, Council, Bouquet); This set of terms includes team, council, and bouquet. The terms team and council both refer to groups of people working together towards a common goal, or for decision-making purposes, respectively. However, a bouquet stands out as it refers to a collection or arrangement of flowers, rather than a group of people or entities.
Fourth option: (Shoal, Flock, Chorus); In this group, shoal and flock represent groups of living entities. Shoal specifically refers to a group of fish, while flock is used to indicate a group of birds or sheep. The term chorus, however, is different as it refers to a collective singing group or a particular segment of a song, and does not indicate a grouping of living entities.

So, in each set, three words relate to collective groups, while in the first option, one word stands out of the given set as it doesn't belong to the collective grouping. Hence, the first option is correct.