Answer:
(C) Not petting the dog unless he obeys
Explanation:
Negative reinforcement is defined as a type of operant conditioning where a pleasurable reinforcement is taken away from the conditioning target, in order for the target to exhibit the expected behavior. Thus, since a dog finds being petted pleasurable, not giving the dog a petting unless it obeys commands is a form of negative reinforcement.
The other options are components of operant conditioning: (A) is a form of negative punishment, while (B) is a form of positive punishment. (D) is possibly a form of shaping.