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: Physiology
[{'content': 'All of the following are true about cardiac muscles, EXCEPT: \nSelect and explain. \nA. Abundant mitochondria are present., B. Has high content of myoglobin, C. 10% energy is provided by anerobic metabolism, D. None of the above', 'role': 'user'}, {'content': "Answer: C \nExplanation: Mammalian heas have an abundant blood supply, numerous mitochondria, and a high content of myoglobin, a muscle pigment that can function as an O2 storage mechanism. Normally, less than 1% of the total energy liberated is provided by anaerobic metabolism. Ref: Ganong's Review of Medical Physiology 23rd edition, Chapter 5.", 'role': 'assistant'}]