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: Social & Preventive Medicine
Test of significance for comparing means of 2 group is 
Select and explain. 
A. Paired t - test, B. Unpaired t - test, C. Sign test, D. Chi - square test
B: Unpaired t - test
Answer: B: Unpaired t - test 
Explanation: Paired student t - test ⇒ Comparision of means in paired data of 1 group.
Un - Paired student t - test ⇒ Comparision of means between 2 group.
ANOVA test ⇒ Comparision of means if ≥ 3 groups.