Operant conditioning applies to and involves associations between involuntary behavior; stimuli involuntary behavior; behavior and consequences voluntary behavior; behavior and consequences voluntary behavior; stimuli

I believe the answer is: voluntary behavior; behavior and consequences
An operant conditioning occurs when the behavior of an individual is controlled by the reward and punishment that created by behavior.
For example, when a father scolded his son when he does not put his plate on dishwasher, the son would most likely to voluntarily place the plate because he does not want to receive the negative consequences.