How do i find the differencs between who and whom

Which of the following arguments uses a non sequitur fallacy? a. if we allow students to wear caps to school, soon we'll have to let them wear gang colors. b. you should vote for sylvia for class president because everyone else on the squad is voting for her. c. regulations on motorists should be lifted because factories are a bigger source of pollution. d. the gray wolves of winter falls park should be protected because they need our support.