Atype ii error is committed when a. the sample size has been too small b. not enough information has been available c. a true null hypothesis is mistakenly rejected d. a true alternative hypothesis is mistakenly rejected

The answer in this question is C. A true null hypothesis is mistakenly rejected. By the definition of a type II error is the event where you've failed to reject the null and consequently have to accept it, but the alternate is actually the correct choice. So we will go to the choice C.