Which of the following statements about null hypothesis significance testing is correct?

I. If the frequency of occurrence for a particular statistic is very low (< 5%), then assume it came from a different sampling distribution.

II. Null hypothesis significance testing tests the probability that the alternative hypothesis is true. It compares the sample mean with the sampling distribution of the experimental group.

III. If the probability of occurrence of the sample statistic is high (> 5%), then you should reject the null hypothesis and conclude that the effect is reliable.

IV. If there is a confound in your study, then the probability of getting your sample's statistic will be increased.