Answer: Option (C) is the correct answer.
Step-by-step explanation:
Clouds are basically condensed vapors and they can be formed at different altitudes and height.
For example, typically clouds appear between 6,500 feet to 20,000 feet.
Whereas when tiny droplets are suspended into the atmosphere then it is known as fog. And fog, generally appears at lower altitude than clouds.
Therefore, we can conclude that compared with clouds, fogs are at lower altitudes.