Answer:
The answer is A. The return of the smog is linked to the burning of fossil fuels.
Step-by-step explanation:
Smog is a condition of air pollution where the smoke is mixed with the Fog. The main reason for increasing smog is burning of fossil fuel like coal and petroleum. Smog is clearly visible and contain toxic compounds like sulfur oxide and nitrogen oxide and other particles. Smog not only cause problem for vision it also cause serious respiratory problems like asthma.