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: Medicine
All the following conditions cause type I respiratory failure EXCEPT- 
Select and explain. 
A. Acute asthma, B. Pulmonary edema, C. Pneumonia, D. Brainstem lesion
D: Brainstem lesion
Answer: D: Brainstem lesion 
Explanation: Type l respiratory failure occurs when alveolar flooding and impaired ventilation of pa of a lung occur(asthma or pneumonia),resulting in hypoxia and normo/hypocapnia(PaO2 <8 kPa and PaCO2 <50 mmHg).Alveolar flooding may be a consequence of pulmonary edema,pneumonia,or alveolar hemorrhage.Causes of type l respiratory failure include acute asthma,pulmonary edema, pneumonia,lobar collapse,pneumothorax,pulmonary embolus,ARDS,lung fibrosis,COPD,right-to-left shunts. Brainstem lesion leading to impaired CNS drive to breathe can lead to type ll respiratory failure with hypoxia and hypercapnia. Ref:Harrison's medicine-18th edition,page no:2199,2200.