Which correctly describes a cause-and-effect relationship in this excerpt? a) cause: people had to walk a half mile to catch the bus. effect: the bus company refused to extend the bus line. b) cause: people had to walk across a bridge to catch the bus. effect: mr. nixon protested to the bus company. c) cause: the bus company refused to extend the bus line. effect: mr. nixon drove his car into town. d) cause: mr. nixon asked the bus company to make a new stop. effect: the bus company refused to make a new stop.