The correct answer is "C".
In comparison to the other options, lumber is the resource that will recover its level of supply in the shortest time frame. Lumber comes from trees, which, depending on their species, take from 5 to 10 years to fully develop. Many environmental efforts are being made nowadays in order to increase the planting of trees, as well as reducing the consumption of them.
The other 3 options represent fossil fuels that took millions of years to form. Therefore, the idea of expecting a renewal of these sources in a short period of time is not feasible.