This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
[{'content': "A study measures a patients's serum cholesterol before and after a new lipid lowering therapy has been given.What type of significance test should be used to analyze the data? \nSelect and explain. \nA. Paired t test, B. Student t test, C. Chi square test, D. Pearson's coefficient", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ref:Park's Textbook of Preventive and Social Medicine 25th Ed", 'role': 'assistant'}]