Given the following abstract data type: fun NewSeth nil end fun (IsMember E x) ...8this oz code is skipped, but you may assume this code is correct end fun Add E X XIE end is the following definition a correct abstract data type? fun (Extend E x if IsMember E X) then E else XIE end end It is a correct ADT definition, since everything is encapsulated; It is a correct ADT definition, since everything is inherited; No, it violates the abstract data type philosophy: X IE should be (Add EX) Error: "IsMember is not visible to Extend" None of the above