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
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? 
Select and explain. 
A. Paired t test, B. Student t test, C. Chi square test, D. Pearson's coefficient
A: Paired t test
Answer: A: Paired t test 
Explanation: Ref:Park's Textbook of Preventive and Social Medicine 25th Ed