Choose the word which is different from the rest.

Fog
Cloud
Rain
Mist

The answer is C. Rain.

Fog, cloud, and mist are all forms of water vapor in the atmosphere. Fog is a cloud that forms at ground level, while clouds form higher up in the atmosphere. Mist is a thin fog that is not as dense as fog. Rain is water that falls from clouds to the ground.

Rain is the only option that is not a form of water vapor in the atmosphere. Rain is water that has condensed from clouds and fallen to the ground.