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
All are true regarding students t-test, except- 
Select and explain. 
A. Standard error of mean is not estimated, B. Standard population is selected, C. Two samples are compared, D. Student's t- test map is required for calculation
A: Standard error of mean is not estimated
Answer: A: Standard error of mean is not estimated 
Explanation: Ref:Parks 23rd edition pg 852 Student T test requires mean and SD Tests of significance: Qualitative: Chi- square : 2 or more than 2 groups Mc Nemar test : 1 group. ( before and after intervention) Quantitative: Paired T test: 1 group Student T test/ unpaired T test: 2 groups Anova: more than 2 groups.