Metamorphic rock forms as a result of heat and pressure.
A. heat and pressure.
The best answer is reduction in acid rain.
Acid rain is rainfall which has been rendered acidic by pollutants in the atmosphere. This kind of rain is typically harmful to forests and lakes.
The main cause of acid rain is human activities. The burning of fossil fuels such coal in electrical generating plants and crude oil products such as gasoline and diesel in car engine releases sulphur dioxide and nitrogen oxide into the atmosphere.
These compounds mix with water very high up in the atmosphere and form acid pollutants which fall on the ground as acid rain.
Use of clean energy will eliminate burning of fossil fuels and thus no acid rain will be produced.
The time required for the moon to orbit around the earth is slightly longer than the earth rotation on its axis. The moon rotates in the same direction that the earth rotates on its axis. Thus, the moon's full rotation requires another 50min or 25 minutes per crossing of the earth's meridian.
C is your answer to your question