This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pathology
Histopathology of mitral Valve prolapsed shows what kind of change? 
Select and explain. 
A. Myxomatous, B. Fibrinoid, C. Granulomatous, D. Fibrous
A: Myxomatous
Answer: A: Myxomatous 
Explanation: In myxomatous degeneration of the mitral valve, one or both mitral leaflets are "floppy" and prolapse--they balloon back into the left atrium during systole. Mitral valve prolapse is a primary form of myxomatous mitral degeneration affecting some 0.5% to 2.4% of adults; thus, it is one of the most common forms of valvular hea disease in the Western world. Men and women are equally affected. (Robbins Basic Pathology,9th edition,pg no.403)