<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 6-year-old boy presents to the pediatrician with his parents. He fully vaccinated and met most developmental milestones. His fine motor milestones are delayed; at present, he cannot eat by himself and has difficulty in self-dressing. His intelligence quotient IQ is 65. He listens quietly while spoken to and engages in play with his classmates. He neither talks excessively nor remains mute, but engages in normal social conversation. There is no history of seizures and he is not on any long-term medical treatment. On his physical examination, his vital signs are stable. His height and weight are normal for his age and sex, but his occipitofrontal circumference is less than the 3rd percentile for his age and sex. His neurologic examination is also normal. Which of the following is the most likely diagnosis?? A: Autism, B: Tic disorder, C: Attention deficit hyperactivity disorder, D: Intellectual disability, E: Obsessive-compulsive disorder,  <response>: Based on the information provided in the question stem, the key findings are:- 6-year-old boy with delayed fine motor milestones - Cannot eat by himself or dress himself- IQ of 65 below 70-75 indicates intellectual disability- Listens and engages in play appropriately - Engages in normal social conversation- No seizures or long-term medications- Normal vital signs and growth parameters except head circumference 3rd percentile- Normal neurologic examThese findings, especially the delayed fine motor skills, low IQ, and small head circumference, point towards a diagnosis of intellectual disability formerly known as mental retardation. The normal social interaction and conversation make autism less likely. There is no mention of tics or obsessive-compulsive symptoms to support those diagnoses. The description does not suggest attention deficit or hyperactivity.D: Intellectual disability 