Three of the four group of words are alike in some manner. Select the odd group of words.

(Stock, Troupe, Robber)

The logic followed here is:

These words represents different group and collections

(Stock, Troupe, Robber) → Robber does not  represent any group

(Team, Council, Bouquet) → These words represents different group

(Crowd, Army, Herd) → These words represents different group

(Shoal, Flock, Chorus) → These words represents different group