icated by the table. Assume that the associative this mathematical system? system under the given operation? ave an inverse? ociative property. mutative group? t SU I t T I t I S S TISE t s t S 1 U I U I t a. What are the elements of the set in the mathematical system? The elements are (t,s,u,r). (Use a comma to separate answers as needed.) b. What is the binary operation? Choose the correct answer below. A. OB. txu c. Is the system closed?