Question

Which is a cost that comes with using coal as an energy source?

Coal produces less energy than most other energy resources,
Mining coal improves the environment.
Coal will stay plentiful in the United States.
When burned, coal produces pollutants that are released into the air.

Answer 1

When burned, coal produces pollutants that are released into the air.

Step-by-step explanation:

This is the only negative implication and the question mentions a 'cost' which implies a negative connotation or tradeoff when coal is used a energy source.