Simone Taught Her Dog to Sit

Multiple Choice

Simone taught her dog to sit. She also taught her dog to drop anything that he was holding in his mouth. Now, when they play fetch, she first gets her dog to sit, then she throws the ball and when he returns she tells him to drop the ball. Then he sits again, and the game starts all over. Which operant conditioning procedure does this represent?

A) Negative reinforcement
B) Chaining
C) Fading
D) Shaping