Which of the following accurately describes how the outcome of a hypothesis test and measures of effect size with the independent-measures t statistic are affected when sample variance increases?

a. The likelihood of rejecting the null hypothesis and measures of effect size both increase.

b. The likelihood of rejecting the null hypothesis and measures of effect size both decrease.

c. The likelihood of rejecting the null hypothesis increases and there is little or no effect on measures of effect size.

d. The likelihood of rejecting the null hypothesis decreases and there is little or no effect on measures of effect size.