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.
<span>hydrosphere should be yor answer</span>
The correct answer is - D) Jewish immigrants in Poland who fled to the United States to escape religious persecution and seek safety and new opportunities.
The push factors are the factors that make the people move away from one place to another. They are negative factors, and can be economical, political, because of safety reasons etc.
The Jews that fled Poland in order to feel safe and get new opportunities in life in the United States, based on the religious and ethnic persecution, is a nice example of a push factor. In this case we have a push factor motivated on religious and ethnic hatred, which of course will make the people of the persecuted group feel unsafe, threatened, so they will try to move away if possible because their lives are in danger.