<span>hydrosphere should be yor answer</span>
2 definitions:
an artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication.
a celestial body orbiting the earth or another planet
The answer to your question would be d.aquifer Hope this helps:)
This area would be the tropics if that's what you're asking for If, not leave a comment below for what the question really is.
