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: ENT
Left sides vocal cord palsy is commonly due to - 
Select and explain. 
A. Left hilar bronchial carcinoma, B. Mitral stenosis, C. Thyroid malignancy, D. Thyroid surgery
A: Left hilar bronchial carcinoma
Answer: A: Left hilar bronchial carcinoma 
Explanation: Unilateral left abductor paralysis is most commonly due to a bronchial carcinoma at the left hilum.