This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
[{'content': 'MELAS is an inherited condition which occurs due to deficiency of \nSelect and explain. \nA. Complex I, B. Complex II, C. Complex III, D. All the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke) is an inherited condition due to NADH-Q oxidoreductase (Complex I) or cytochrome oxidase (Complex IV) deficiency. It is caused by a mutation in mitochondrial DNA and may be involved in Alzheimer disease and diabetes mellitus. Reference: Harper; 30th edition; Page no: 135', 'role': 'assistant'}]