Light pollution is caused when
A. The ozone layer is damaged
B. Too much of light sources are used unnecessarily
C. Light sources pointing up to the sky rather than down to earth
D. Sources of light are polluted

Hint:To answer this question, we first need to understand what is pollution. The introduction of hazardous chemicals into the atmosphere is referred to as pollution. Pollutants are the term for these toxic products. Pollutants may come from the environment, such as volcanic ash. They can also be caused by human activity, such as garbage or factory runoff. Pollutants wreak havoc on the environment, including the air, water, and soil.

Complete answer:
Light pollution: The effect of anthropogenic and artificial light in the night environment is known as light pollution. Excessive, misdirected, or obtrusive use of light exacerbates the issue, but even carefully used light fundamentally alters natural conditions. As discussed above in the definition, light pollution is also caused when excessive light Is present.

Hence, option B is the correct answer.

Note:Light pollution became a concern in the early twentieth century, at the same time as cities began to use electric lighting. Another way to cut down on light pollution is to make sure that the light is just shining on what needs to be lit. An example would be putting a shade on a lamp.