Luis is standing at the bus stop watching two busesa red bus and a blue busapproach from a distance. Since he wants to board the red bus, he moves toward the curb once he sees it cut in front of the blue bus, indicating that it's closer to him than the blue bus and therefore will arrive first. What depth cue did Luis use in order to make that inference? Luis is standing at the bus stop watching two busesa red bus and a blue busapproach from a distance. Since he wants to board the red bus, he moves toward the curb once he sees it cut in front of the blue bus, indicating that it's closer to him than the blue bus and therefore will arrive first. What depth cue did Luis use in order to make that inference? Optic flow Size constancy Interposition Texture gradient