Parental is related to Rating. Rating is related to Price. Price is related to Free. 
Cause is the opposite of Prevent. Prevent is related to Starting. Starting is related to Declare. Call is a type of Declare. 
Parental <--RelatedTo--> Rating <--RelatedTo--> Price <--RelatedTo--> Free 
Cause <--Antonym--> Prevent <--RelatedTo--> Starting <--RelatedTo--> Declare <--IsA-- Call 