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: Anatomy
Commonest intrabronchial cause of haemoptysis is 
Select and explain. 
A. Carcinoma lung, B. Adenoma lung, C. Emphysema, D. Bronchiectasis
A: Carcinoma lung
Answer: A: Carcinoma lung 
Explanation: The two most common causes for haemoptysis are bronchitis and bronchiogenic carcinoma. Bronchitis is not provided amongst the options and hence bronchiogenic carcinoma is the single best answer of choice Ref Harrison 19th edition pg 227