This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oral Cavity, Subject name: ENT
Long-standing obstruction due to enlarged tonsils and adenoids can cause: 
Select and explain. 
A. Lett ventricular hypertrophy, B. Bundle branch block, C. Cor pulmonale, D. Cardiac ischaemia
C: Cor pulmonale
Answer: C: Cor pulmonale 
Explanation: Right ventricular hypertrophy and cor pulmonale are seen in long-standing tonsil and adenoid obstruction. It is reversible after adenotonsi llectomy.