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
"Myxoma" of Hea commonly arises from: 
Select and explain. 
A. Left ventricl, B. Left atrium, C. Right ventricle, D. Right atrium
B: Left atrium
Answer: B: Left atrium 
Explanation: Left atrium