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: Biochemistry
[{'content': 'If the molar percentage of guanine in a human DNA is 30%, what is the molar percentage of adenine in that molecule? \nSelect and explain. \nA. 10%., B. 20%., C. 30%., D. 40%.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Guanine base pairs with cytosine which, on a molar basis, will also equal 30% of the DNA. If guanine and cytosine constitute a total of 60% of DNA, the remaining percentage (40%) must be equally divided between the base pairs of adenine and thymine (20% + 20%).', 'role': 'assistant'}]