Option A and B. They are the organelle of locomotion for most bacteria capable of motility. And, a motile response to an environmental stimulus. Bacterial flagella are helical filaments made up of the protein flagellin 20-nanometer-thick with a rotary motor at its base which can turn clockwise or counterclockwise. Like the multicellular flagellum the primary role of the flagellum is locomotion, bacterial mobility, but it often functions as a sensory organelle in response to external stimuli like exposure to chemicals and temperatures outside the cell.
