What is the most reasonable explanation for Hank’s behavior in the following scenario? Hank is fifteen. He is in the honors program at school. He likes literature and chemistry. He has trouble knowing how many commitments to take on. Sometimes he stays out late with friends although he knows he will pay a price later. And sometimes he goes along with friends when they suggest doing something that is a little risky.

His prefrontal cortex is still developing.

He has not yet entered the abstract operations stage.

His brain did not undergo myelination at the expected time.

He has an impulse control disorder.