The most significant problems associated with using coal as an energy source are its environmental damage caused by mining and its contribution to air and water pollution.
The correct answers are:
A. Strip mining is environmentally detrimental. This is true because strip mining destroys ecosystems, removes topsoil, and contaminates water sources.
D. Underground mining is dangerous to humans. This is true because miners face risks of cave-ins, explosions, and exposure to harmful dust and gases.
E. Burning coal causes acid rain. This is true because sulfur dioxide and nitrogen oxides released from burning coal combine with water vapor in the atmosphere to form acid rain, which harms forests, lakes, and other ecosystems.
While the other options are not entirely incorrect, they are less relevant to the main problems associated with coal as an energy source:
B. Burning coal releases ammonia. While coal combustion does release some ammonia, it's not a major pollutant compared to others like sulfur dioxide and nitrogen oxides.
C. Worldwide coal resources are diminishing. This is true in the long term, but coal reserves are still vast and not a major concern in the near future.