An office building has 8 floors above the ground. On a line graph that models the average number of times the elevator stops on each floor each day, which values will be the x-coordinates? A) D = {1, 2, 3, 4, 5, 6, 7, 8} B) D = {0, 1, 2, 3, 4, 5, 6, 7,} C) D = {0,1, 2, 3, 4, 5, 6, 7, 8} D) D = {-1, -2, -3, -4, -5, -6, -7, -8}