In Testing the Difference Between Two Population Means for Which

In testing the difference between two population means for which the population variances are unknown and assumed to be equal, two independent samples are drawn from the populations. Which of the following tests is appropriate? $\begin{array}{|l|l|}\hline A&z \text {-test. }\\\hline B&\text { Equal -variances } t \text {-test. }\\\hline C& F \text {-test. }\\\hline D&\text { Matched pars } t \text {-test. }\\\hline\end{array}$