This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Physiology
There is mutation of gene coding for the ryanodine receptors in malignant hypehermia. Which of the following statements best explains the increased hea production in malignant hypehermia 
Select and explain. 
A. Increased muscle metabolism by excess of calcium ions, B. Thermic effect of food, C. Increased sympathetic discharge, D. Mitochondrial thermogenesis
A: Increased muscle metabolism by excess of calcium ions
Answer: A: Increased muscle metabolism by excess of calcium ions 
Explanation: Malignant hypehermia (MH) or malignant hyperpyrexia is a rare life-threatening condition that is usually triggered by exposure to ceain drugs used for general anesthesia -- specifically the volatile anesthetic agents and succinylcholine, a neuromuscular blocking agent. In susceptible individuals, these drugs can induce a drastic and uncontrolled increase in oxidative metabolism in skeletal muscleRef: Ganong&;s review of medical physiology; 24th edition; page no: 320