Which of the following substitutions can reduce air pollution?
a. using a bike instead of a car
b. using dumps instead of landfills
c. using coal instead of oil
d. using fireplaces instead of a wind farms

The best substitution that can help in reducing air pollution is option A. using a bike instead of a car. It is known that vehicle emission is the top reason of the worsening case of air pollution. These emissions consist of nitrogen oxides and carbon monoxide which can cause several respiratory health problems.

The troposphere gets warmer as altitude increases.