<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 3-year-old boy is brought in by his mother because she is concerned that he has been acting differently recently. She says he no longer seems interested in playing with his friends from preschool, and she has noticed that he has stopped making eye contact with others. In addition, she says he flaps his hands when excited or angry and only seems to enjoy playing with objects that he can place in rows or rigid patterns. Despite these behaviors, he is meeting his language goals for his age single word use. The patient has no significant past medical history. He is at the 90th percentile for height and weight for his age. He is afebrile and his vital signs are within normal limits. A physical examination is unremarkable. Which of the following is the most likely diagnosis in this patient?? A: Autism spectrum disorder, B: Aspergers disorder, C: Retts disorder, D: Pervasive developmental disorder, not otherwise specified, E: Childhood disintegrative disorder,  <response>: Based on the description in the question stem, the 3-year-old boy is exhibiting symptoms such as lack of eye contact, repetitive hand movements, restricted interests, and difficulties with social interactions, which are characteristic of autism spectrum disorder ASD. The key aspects that point to ASD are:- Lack of eye contact- Flapping hands when excited or angry - Only enjoys activities with rigid patternsrows- Loss of interest in social interactionsAspergers disorder, Retts disorder, childhood disintegrative disorder and PDD-NOS are less likely based on the symptom presentation. Aspergers lacks language delay. Retts primarily affects girls. Childhood disintegrative disorder involves regression after normal development. PDD-NOS is a possibility but ASD seems most specific.A: Autism spectrum disorder 