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
Waking up at night, screaming with fear, at 2.5 years age, is generally a manifestation of: 
Select and explain. 
A. Organic illness, B. Normal development pattern, C. Castration anxiety, D. Separation anxiety
D: Separation anxiety
Answer: D: Separation anxiety 
Explanation: 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