Answer:

Explanation:
Take sum of torques at the point the step touches the wheel, that eliminates two torques
Σ
Since we are looking for when the wheel just starts to rise up N-> 0 so no torque due to normal force

The perpendicular lever arm for the F force is R-h

And the T of gravity according to the image

Σ





B is the answer because it takes millions of years to form these fossil fuels and everyday we use way more than we can find we may have a surplus for now but we may run out sooner than some think