Final answer:
Cardiac tamponade is not a secondary cause of mitral valve prolapse.
Step-by-step explanation:
Secondary causes of mitral valve prolapse include atrial septal defect, bicuspid aortic valve, and primary pulmonary hypertension. Cardiac tamponade is not a secondary cause of mitral valve prolapse. Cardiac tamponade refers to the accumulation of fluid in the pericardial space, which can compress the heart and interfere with its normal function. It does not directly affect the mitral valve. Therefore, the correct answer is C. Cardiac tamponade.