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
Which of the following is abnormal? 
Select and explain. 
A. Respiratory rate >40/min in a child between 2-12 months age, B. Respiratory rate >50/min in a child between 2-12 months age, C. Respiratory rate >30/min in a child between 1-5 years age, D. Respiratory rate >50/min in a child between < 2 months age
B: Respiratory rate >50/min in a child between 2-12 months age
Answer: B: Respiratory rate >50/min in a child between 2-12 months age 
Explanation: b. Respiratory rate >50/min in a child between 2-12 months age(Ref: Nelson's 20/e p 2088-2093, Ghai 8/e p 379-381)Cut-off for fast breathing:Age<2 months2-12 months12-60 monthsRespiratory Rate>=60/min>=50/min>=40/min