<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 7-year-old boy is brought to the physician by his mother for the evaluation of abdominal pain and trouble sleeping for the past 6 months. His mother says he complains of crampy abdominal pain every morning on school days. He started attending a new school 7 months ago and she is concerned because he has missed school frequently due to the abdominal pain. He also has trouble falling asleep at night and asks to sleep in the same room with his parents every night. He has not had fever, vomiting, diarrhea, or weight loss. He sits very close to his mother and starts to cry when she steps out of the room to take a phone call. Abdominal examination shows no abnormalities. Which of the following is the most likely diagnosis?? A: Separation anxiety disorder, B: Normal behavior, C: Irritable bowel syndrome, D: Conduct disorder, E: Acute stress disorder,  <response>: This is a clinical vignette describing a 7-year-old boy with abdominal pain and sleep issues that started around the time he began attending a new school 7 months ago. The abdominal pain occurs in the mornings on school days and has caused him to miss school frequently. He also has trouble falling asleep and now asks to sleep in his parents room. He appears anxious, sitting close to his mother and crying when she steps out briefly. His abdominal exam is normal. Based on the timeline of symptoms beginning with a new school, the symptoms being worse around school days, his apparent anxiety and separation issues, and normal abdominal exam, this is most consistent with a diagnosis of separation anxiety disorder. The other choices can be ruled out: there are no conduct issues described that would support conduct disorder, no diarrhea or other symptoms to suggest IBS, and the prolonged timeline does not fit with acute stress disorder. While some degree of anxiety is normal with a new school, his level of symptoms and impairment point to a diagnosis of separation anxiety disorder.A: Separation anxiety disorder 