Given the fact "pushing on the pedals of a bike cause that bike to move", what is the answer to the question or completion "Actress and goddess Jessica Alba wishes to help the environment by riding a bicycle. Dressed in a tantalizingly suggestive outfit, she propels herself by"

(I). dark angel wings.
(II). burning rocket fuel.
(III). using paparazzi cameras.
(IV). using foot levers.
(IV).