Decision is related to Mistake. Mistake is a synonym of Confuse. 
Period is a synonym of Tide. Time is etymologically related to Tide. Time is a type of Mystery. Mystery is related to Spy. 
Decision <--RelatedTo--> Mistake <--Synonym--> Confuse 
Period <--Synonym--> Tide <--EtymologicallyRelatedTo-- Time --IsA--> Mystery <--RelatedTo--> Spy 