Why is mining for coal a long-term concern? A. It is being replenished faster than it can be mined.
B. The supply will eventually be exhausted.
C. New methods of mining need to be developed.
D. The demand for coal is diminishing.

B

Explanation:

Coal is a non-renewable resource, so the supply can't produce faster than we can mine it.

Is B: the supply will eventually be exhausted.

Explanation:

there is only so much coal in the world as in many other elements. That is why we are looking for more appropriate and resourceful way of supplying energy and it is a lot safer for the workers involved