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
A person is having normal lung compliance and increased airway resistance. The most economical way of breathing for him: 
Select and explain. 
A. Rapid & deep, B. Rapid & shallow, C. Slow & deep, D. Slow & sallow
C: Slow & deep
Answer: C: Slow & deep 
Explanation: C i.e. Slow and deep