Determine is related to Measure. Measure is related to Rule. Rule is related to Serving. 
Legal is related to Plea. Plea is a type of Answer. Answer is the opposite of Mistake. 
Determine <--RelatedTo--> Measure <--RelatedTo--> Rule <--RelatedTo--> Serving 
Legal <--RelatedTo--> Plea --IsA--> Answer <--Antonym--> Mistake 