On a distant planet, Ralph ran into a creature with multiple arms and multiple legs. Each arm has 6 fingers and each leg has 9 toes. On any one of these creatures, the total number of fingers and toes, D, can be described with the equation D = 6x + 9y. In this equation, what does the variable x represent? A. the number of arms the creature has. B. the number of legs the creature has. C. the number of fingers the creature has. D. the number of toes the creature has.