The world's high rate of coal consumption is causing many negative impacts on the environment. Solving this problem involves a combination of different tactics. Which of the following is nof a conservation tactic that would help solve the problems related to coal consumption?

A. Replanting forests to help offset the carbon emissions from coal power plants

B. Engineering new versions of common household goods that require less electricity

C. Developing more efficient methods of mining coal

D. Increasing the usage of pollution filters in coal power plants

C. Developing more efficient methods of mining coal