When Statisticians Talk About Effect Size, They Are Referring to $\alpha$

Multiple Choice

When statisticians talk about effect size, they are referring to

A) the p value obtained from a test such as a t test
B) the difference between the mean of the population the sample is from and the mean of the null hypothesis population
C) whether an $\alpha$ level of .05 or .01 was used
D) whether or not the test statistic was in the rejection region.