Nearly half of the pollution caused by burning fossil fuels comes from
a. factories.
b. power plants.
c. home furnaces.
d. motor vehicles.

Burning fossil fuels, ie petroleum products and coil, is a very big problem that causes pollution, the greenhouse effect and global warming, as well as a harmful  effect on human health. In combustion of fossil fuels, harmful substances and global warming emissions are emitted, ie air pollutants. According to official data, almost half of the pollution caused by burning fossil fuels comes from motor vehicles.

The answer is: d.