Which of the following are the objectives for having a controlled vocabulary: 

(A).  to treat quasi-synonyms in the same way as synonyms

(B). to promote the consistent representation of the subject matter of documents by indexers and searchers, 

(C). to facilitate the conduct of a comprehensive search, by bringing together in some way, the terms that are most closely related semantically. 

(D). to facilitate the conduct of a comprehensive search, by taking apart in some way, the terms that are most closely related semantically.