This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Behavioral Disorders in Children, Subject name: Pediatrics
[{'content': 'Waking up at night, screaming with fear, at 2.5 years age, is generally a manifestation of: \nSelect and explain. \nA. Organic illness, B. Normal development pattern, C. Castration anxiety, D. Separation anxiety', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Separation anxiety developmentally normal when it begins about 10 months of age and tapers off by 18 months By 3 yr of age, most children can accept the temporary absence of their mother or primary caregiver', 'role': 'assistant'}]