This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pediatrics
WHO criteria for hospital admission in pneumonia ? 
Select and explain. 
A. High fever, B. Nasal flaring, C. Difficulty in breathing, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: CURB-65 uses the following criteria to assess the patient&;s severity of illness: confusion; uremia with blood urea nitrogen (BUN) level of 20 mg/dL or higher; respiration rate of 30 or more breaths per minute; systolic blood pressure lower than 90 mm Hg or diastolic blood pressure 60 mm Hg or lower; and age 65 or older . Reference: GHAI Essential pediatrics, 8th edition