Approach is a synonym of Way. Way is a type of Choice. Choice is a synonym of Select. Select is a synonym of Opt. 
Cake is related to Tower. Tower is related to Defensive. 
Approach <--Synonym--> Way --IsA--> Choice <--Synonym--> Select <--Synonym--> Opt 
Cake <--RelatedTo--> Tower <--RelatedTo--> Defensive 