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': 'Base substitution of GAC (Asp) to GAG (Glu) is an example of: \nSelect and explain. \nA. Point mutation, B. Silent mutation, C. Non-sense mutation, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Point mutation', 'role': 'assistant'}]