Question

what is the envelope of gas that surrounds earth?
a. atmosphere
b. biosphere
c. cryosphere
d. geosphere
e. hydrosphere

Explanation:

The atmosphere is the layer of gases surrounding the Earth. The biosphere is the global sum of all ecosystems. The cryosphere is the frozen water part of the Earth system. The geosphere is the solid part of the Earth. The hydrosphere is the total amount of water on a planet.

Answer:

A. atmosphere