The correct answer is C. Radiation.
A physical pollutant is a substance or energy that can change the physical properties of the environment. Radiation is a form of energy that can be harmful to humans and other living things. It can cause cancer, birth defects, and other health problems. Radiation can come from natural sources, such as the sun, or from man-made sources, such as nuclear power plants and X-ray machines.
Water, air, and plants are not physical pollutants. Water is a necessary part of life, and it is not harmful unless it is contaminated with chemicals or other pollutants. Air is also necessary for life, and it is not harmful unless it is polluted with smoke, dust, or other pollutants. Plants are living things, and they are not harmful unless they are poisonous.
Here are some additional details about each option:
- Water is a colorless, odorless, tasteless liquid that is essential for life. It covers about 71% of the Earth’s surface, and it is found in oceans, lakes, rivers, and glaciers. Water is also found in the atmosphere, in the soil, and in living things.
- Air is a mixture of gases that surrounds the Earth. It is made up of nitrogen (78%), oxygen (21%), argon (0.9%), and other gases in small amounts. Air is essential for life, because it provides oxygen for breathing.
- Plants are living things that make their own food through photosynthesis. They are found in all parts of the world, and they come in a variety of shapes and sizes. Plants are important for the environment, because they help to clean the air and water, and they provide food and shelter for animals.
- Radiation is a form of energy that can travel through space and matter. It can be produced by natural sources, such as the sun, or by man-made sources, such as nuclear power plants and X-ray machines. Radiation can be harmful to humans and other living things, and it can cause cancer, birth defects, and other health problems.