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: Pathology
Characteristic pathological finding in carcinoid of heart - 
Select and explain. 
A. Fibrous endocordial thickening of right ventricle and tricuspid valve, B. Collagen deposition in wall of right ventricle and tricuspid valve, C. Interstitial fibrous thickening of right ventricle and pulmonary valve, D. Mononuclear inflammatory infiltrate in the wall of right atrium
A: Fibrous endocordial thickening of right ventricle and tricuspid valve
Answer: A: Fibrous endocordial thickening of right ventricle and tricuspid valve 
Explanation: None