This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
During normal inspiration diaphragm goes down by? 
Select and explain. 
A. 1-2 cm, B. 3-5 cm, C. 5-7 cm, D. 7-9 cm
A: 1-2 cm
Answer: A: 1-2 cm 
Explanation: Ans. is 'a' i.e., 1-2 cmIn normal inspiration, the diaphragm descends 1-2 cm into the abdominal cavity producing a pressure difference of 1-3 mm hg and the inhalation of about 500 ml of air.