Smog, e.g.

HAZE

["Think about what smog creates in the air that makes it difficult to see."]

The clue "Smog, e.g." leads to the answer "HAZE" through a straightforward example. "Smog" is a type of air pollution that combines smoke and fog, creating a thick, visible haze in the air. The clue uses "e.g." to indicate that "smog" is an example of something. Since "haze" is a general term for reduced visibility due to particles in the air, and smog is a specific type of haze, the answer to the clue is "HAZE." There is no complex wordplay or pun involved; it's a direct categorical relationship.