lets analize the question
best describes earths atmosphere
it cant be AN EMPTY SPACE because earths atmosphere has a function
It Cant be A THIN TOWEL THAT DOES LITTLE TO PROTECT THE EARTH because the atmosphere protects us from UV (UltraViolet ) RADIATION
it Cant Be A LARGE CLOUD THAT GENERATES THE EARTHS ELECTROMAGNETIC FIELD because earths electromagnetic Field is generated by Earths Core
A BIG BLANKET ABSORBING THE SUNS HEAT is a description of the Atmosphere Because it shields us from The UV RADIATION And Absrobs the right amount of sunlight keeping the planet warm through insulation, and preventing extremes between day and night temperatures.
SO the Answer will have to Be A BIG BLANKET ABSORBING THE SUNS HEAT