Answer:
all possible reinforcers must be withheld.
Explanation:
Extinction in psychology means when a behavior happens because of a reinforcement or reinforcing stimulus, if we remove the stimulus, the behavior gradually disappears.
So, to extinct a response or behavior, the best possible way is removing or withholding all possible reinforeces. The other options i.e. unpredictable reinforcement, frequent punishment, consistent punishment, and attention to proper responses may cause resistance to distinction.