Several days after a myocardial infarction, a 60-year-old man develops a sudden onset of a new pansystolic murmur along with a diastolic flow murmur. Workup reveals increased left atrial pressure that develops late in systole and extends into diastole. Which of the following is the most likely cause of the abnormalities present in this individual?
A.
Thrombosis of the left atrial cavity
B.
Rupture of a papillary muscle
C.
Rupture of the left ventricular wall
D.
Aneurysmal dilation of the left ventricle
E.
Obstruction of the aortic valve