This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Introduction, Subject name: Pathology
[{'content': 'The approx. number of genes contained in the human genome is: \nSelect and explain. \nA. 40,000, B. 20,000, C. 80,000, D. 1,00,000', 'role': 'user'}, {'content': 'Answer: B \nExplanation: There are roughly 3.2 billion DNA base pairs in the human genome. Out of the total genome there are about 20,000 protein encoding genes,which comprises only 1.5% of the genome.', 'role': 'assistant'}]