Cluster is related to Group. Group is the opposite of Crowd. Crowd is the opposite of Company. Company is related to Other. 
Carry is a type of Transportation. Bus can be used for Transportation. 
Cluster <--RelatedTo--> Group <--Antonym--> Crowd <--Antonym--> Company <--RelatedTo--> Other 
Carry --IsA--> Transportation <--UsedFor-- Bus 