What is the tropopause?

the boundary between the troposphere and the ionosphere

the boundary between the troposphere and the stratosphere

the boundary between the troposphere and the mesosphere

the boundary between the troposphere and the exosphere

Explanation:

it's the boundary between the troposphere and the the stratosphere

answer;

-phase iii

explanation;

phase three begins with the transition of a recovered individual to a phase three team of the appropriate service. this phase usually takes place at a military medical facility in the united states. one of the goals of phase three is family reunification.