Fred is playing the slot machines. After a certain number of plays, he wins a few coins, but Fred is unable to determine how many plays he needs to win.
Which of the following statements is true? A. Fred is on a fixed-interval schedule of reinforcement. B. Fred is on a variable-interval schedule of reinforcement. C. Fred is on a fixed-ratio schedule of reinforcement. D. Fred is on a variable-ratio schedule of reinforcement.
