Equivalence testing is carried out by performing two hypothesis tests, allowing a modified version of the null hypothesis to be accepted. The modified version of the null hypothesis is accepted if:
A.) Either one of the two tests leads to rejection of their null hypothesis.
B.) Both of the tests lead to rejection of their null hypotheses.
C.) Either one of the two tests leads to failure to reject their null hypothesis.
D.) Both of the tests lead to failure to reject their null hypotheses.