Fact 1: Pushing on the pedals of a bike cause that bike to move. Fact 2: Bike commuting truly is green but bike commuting is difficult. Given the two facts above, green what can be accomplished through pushing on pedals?

Select from the following.
(1). commuting.
(2). Plants growth.
(3). walking.
(4). driving.
(5). Heart rate.
(6). running.
(7). horse-riding.
(8). Movement.
The answer is:
(1).