When driving in fog or snow,
a. use your high beams.
b. use your low beams.
c. drive at the posted speed limit.

c. drive at the posted speed limit.

Driver should be wary in these conditions. 
 Although snow, fog and acid rain is known as acidic pollutants that occur when sulfur dioxide in the atmosphere is oxidized in the presence of nitrogen dioxide. These two compounds can be easily dissolved in water and they can be carried far by the wind. Since these compounds can travel long distances, they tend to become part of the rain, snow, sleet, and fog that are experienced on certain days. 

The increase of these acidic pollutants is mainly caused by human activities. Power plants, fossil fuels, and coals are some of the sources of these chemicals that are released in the atmosphere.