Read the scenario below and answer the question that follows.Duke is practicing his spelling in the classroom. Duke is going to receive reinforcement after six demonstrations of the target behavior, which is spelling a word correctly. Which of the following statements is true?A.Duke is on a fixed-interval schedule of reinforcement.B.Duke is on a variable-interval schedule of reinforcement.C.Duke is on a fixed-ratio schedule of reinforcement.D.Duke is on a variable-ratio schedule of reinforcement.