A Powerful Women's Group Has Claimed That Men and Women $H_{0}: \pi_{M}-\pi_{W} \neq 0$

A powerful women's group has claimed that men and women differ in attitudes about sexual discrimination. A group of 50 men (group 1) and 40 women (group 2) were asked if they thought sexual discrimination is a problem in the United States. Of those sampled, 11 of the men and 19 of the women did believe that sexual discrimination is a problem. Assuming W designates women's responses and M designates men's, which of the following are the appropriate null and alternative hypotheses to test the group's claim?

A) $H_{0}: \pi_{M}-\pi_{W} \neq 0$ versus $H_{1}: \pi_{M}-\pi_{W}=0$
B) $H_{0}: \pi_{M}-\pi_{W}=0$ versus $H_{1}: \pi_{M}-\pi_{W} \neq 0$
C) $H_{0}: \pi_{M}-\pi_{W} \leq 0$ versus $H_{1}: \pi_{M}-\pi_{W}>0$
D) $H_{0}: \pi_{M}-\pi_{W} \geq 0$ versus $H_{1}: \pi_{M}-\pi_{W}<0$