In Testing the Difference Between Two Population Means, for Which

Short Answer

In testing the difference between two population means, for which the population variances are unknown and are not assumed to be equal, two independent samples of large sizes are drawn from the populations. Which of the following tests is appropriate? $\begin{array}{|l|l|}\hline A.&\text { Z-test. } \\\hline B.&\text { Pooled-variances } t \text {-test. } \\\hline C.&\text { Unequal variances } t \text {-test. } \\\hline D.&\text { Matched pars } t \text {-test. } \\\hline \end{array}$