What is Earths biosphere described as?

Since scientists have not found organisms beyond planet Earth, the biosphere is defined as the parts of Earth where life exists. The biosphere is made of three parts, called the lithosphere, atmosphere and hydrosphere.

Explanation:

i hope this helped

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.