Air pollution is severe in

Cities
Industrialised areas
Densely populated areas
all of these

The correct answer is D. Air pollution is severe in cities, industrialized areas, and densely populated areas.

Air pollution is a major environmental problem that affects people all over the world. It is caused by the release of harmful pollutants into the air, such as particulate matter, ground-level ozone, and carbon monoxide. These pollutants can cause a variety of health problems, including respiratory problems, heart disease, and cancer.

Cities are particularly vulnerable to air pollution because they are often home to large populations of people and industries that emit large amounts of pollutants. Industrialized areas are also at risk for air pollution, as they often have high concentrations of factories and other sources of pollution. Densely populated areas are also at risk, as they often have high levels of traffic congestion and other sources of pollution.

There are a number of things that can be done to reduce air pollution, including:

  • Reducing emissions from vehicles and other sources of pollution
  • Investing in renewable energy sources
  • Planting trees and other vegetation
  • Educating people about the dangers of air pollution

By taking these steps, we can help to reduce air pollution and improve the health of people around the world.

Here is a brief explanation of each option:

  • Option A: Cities. Cities are often home to large populations of people and industries that emit large amounts of pollutants. This makes them particularly vulnerable to air pollution.
  • Option B: Industrialized areas. Industrialized areas are also at risk for air pollution, as they often have high concentrations of factories and other sources of pollution.
  • Option C: Densely populated areas. Densely populated areas are also at risk, as they often have high levels of traffic congestion and other sources of pollution.
  • Option D: All of these. Air pollution is severe in cities, industrialized areas, and densely populated areas.