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
[{'content': 'Most common complication of cardiac catheterization is: \nSelect and explain. \nA. Vascular Access Site Bleeding, B. Arrhythmia, C. Contrast reaction, D. Perforation of hea chamber', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer is A (Vascular Access Site Bleeding) The most common complication of cardiac catheterization is bleeding from the vascular access site. This may be seen either early or late after catheterization and may manifest as ove bleeding or as a hematoma.', 'role': 'assistant'}]