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: Medicine
The most common cardiac involvement in rheumatoid arthritis - 
Select and explain. 
A. Pancarditis, B. Pericarditis, C. Myocarditis, D. Endocarditis
B: Pericarditis
Answer: B: Pericarditis 
Explanation: None