What description refers to stratus clouds

The given question is incomplete, the complete question is:

Which description refers to stratus clouds?

are thin and wispy

are round and fluffy

cover all or most of the sky

form at high altitudes

The correct answer is that it covers the majority or all the of the sky.

Explanation:

The low layered clouds, which entirely envelopes the sky in the form of a blanket are known as stratus clouds. These clouds are typically grey in appearance. These clouds are known as fog when they are witnessed on the ground or close to the ground. These clouds generally generate a small amount of snow or drizzle.  

The formation of stratus clouds generally takes place above 2000 meters of the surface of the Earth.  

what's the question?