Question: In clear weather, a bright light can be seen for a long distance. In conditions of heavy fog, the visibility is greatly reduced. Which of the following explains the reduced visibility?

  Options: 
 A. Light is refracted by water vapor in the air.
 B. Light is scattered by water droplets in the air.
 C. Light is absorbed by water vapor near the ground.
 D. Light is reflected by water droplets on the ground.
Answer: B