This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Basics of genetics, Subject name: Biochemistry
[{'content': 'The commonest form of DNA variation is: \nSelect and explain. \nA. Single nucleotide polymorphism, B. Copy Number Variations (CNVs), C. Transposons, D. Mutations', 'role': 'user'}, {'content': 'Answer: A \nExplanation: SNPs most common polymorphisms. There are 3 million SNPs in the human genome. A single nucleotide at a paicular location is variable', 'role': 'assistant'}]