Which sentence should be revised for clarity? a. guided by a remote control, the robot is able to hover in place as well as fly in all directions, which gives it flexibility. b. this palm-sized robot has the appearance of a large motorized dragonfly. c. its movable wings allow the robot to accompany and film people or objects in motion, so it can film the action as it is happening. d. equipped with a video camera, the robot in flight captures aerial views that provide a unique visual angle.