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: Medicine
All of the following explains diagnosis of Asthma except 
Select and explain. 
A. After administering bronchodilator FEV1 increase to > 200mL within 15 minutes, B. PEFR shows diurnal variation of >20%, C. >12% reversibility in FEV1 on administering bronchodilator, D. Diffusion Lung Capacity for carbon monoxide is decreased
D: Diffusion Lung Capacity for carbon monoxide is decreased
Answer: D: Diffusion Lung Capacity for carbon monoxide is decreased 
Explanation: DLCO is normal in Asthma.