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
A study finds no significant association between two variables but truly there exists a difference. What type of error is this? 
Select and explain. 
A. Type I error, B. Type II error, C. Random error, D. Systematic error
B: Type II error
Answer: B: Type II error 
Explanation: Ans: B. Type II error(Ref: High Yield Biostatistics/p46)Type I ErrorType II ErrorThe null hypothesis is true but rejected (False positive)degProbability of type I error is given by p valuedegSignificance (alpha) level is the maximum tolerable probability of type I errorsdegKeep type I error to be minimum; then results are declared to be statistically significantNull hypothesis is not false but is not rejected/accepted (false negative)degProbability of type II error is given by betadeg