As You Are Examining the Cumulative Record Produced by the Rat

As you are examining the cumulative record produced by the rat you are training in the laboratory, you notice that the graph shows several spots where the line is very steep, followed almost immediately by the line going flat (horizontal) . What does this change from a steep line to a horizontal line most likely mean has happened?

A) A reinforcer occurred for the target behavior
B) A punisher occurred for the target behavior
C) The rate of the target behavior reached its maximum
D) The organism stopped responding to explore other parts of the chamber