Where do clouds form? select three options. at the ground, in the upper atmosphere, near earths surface, where the air has low humidity, where the atmosphere contains few particles.

The answer is the upper atmosphere

Explanation:

Clouds are made of water ice crystals that are so little and light so that they can stay in the air. All air contains liquid water, but close to the ground is usually in the appearance of an unseen gas called water vapor. The water vapor becomes cools as the warm air rises. The warm air holds much water vapor than the cool air. Part of the water vapor condenses into tiny pieces of dust particle that floats in the air and form a little droplet around each dust particle. When all these droplets come together they become a cloud.  

the correct answer is 2 and 4