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
Rasmussen's aneurysm is a 
Select and explain. 
A. Dilated vessel in a tubercular lung cavity, B. Dilated of the root of aoa in valvular stenosis, C. Dilated aoa in syphilitic affection, D. Dilated renal vessel in hypeensive renal disease
A: Dilated vessel in a tubercular lung cavity
Answer: A: Dilated vessel in a tubercular lung cavity 
Explanation: In tuberculosis,hemoptysis can occur due to rupture of a dilated vessel in a tuberculous cavity.It is known as Rasmussen's aneurysm. Ref:Harrison's medicine-18th edition,page no:1345.