Robert’s teacher, Martha, has complained about his behavior on several occasions. According to Martha, Robert cannot focus in class and is constantly distracted. She also mentioned that Robert is extremely active and very impulsive by nature. If Robert were to be taken by his teacher to Dr. Miller, a psychiatrist, he is likely to be diagnosed with

A) attention-deficit/hyperactivity disorder.
B) borderline personality disorder.
C) autism spectrum disorder.
D) mild neurocognitive impairment.