I have no idea what that means but the answer is b
The answer is 800 meters.
You find this by taking the total distance of the first lap and doubling it. You could also find it by adding 400 meters to 400 meters, which would total at 800 meters
Thy decompose dead organisms, and it turns into better soil.
It is called c) a protien. which proteins are found in pretty much every living thing