A touch gesture can comprise multiple MotionEvents involving multiple pointers. Which one of following statements is true about MotionEvents and the pointers that they represent? A. Each pointer has a unique ID that stays constant throughout the gesture. B. Each pointer has a unique index that stays constant throughout the gesture. C. Multiple Pointers with an ACTION_POINTER_DOWN code can be contained in the same MotionEvent. D. Gestures always end with the ACTION_CANCEL action code.