Solution:
It is the system of earth with orbiting satellites, transmitting signals continuously towards the earth,which enable the position of receiving device on near the earth's surface to be accurately estimated from the difference in arrival times.
The Earth system has always changed. But right now it has an additional pressure forcing change: human activites. This force is now global and dominant. The response of the Earth system to this pressure is an important area of science. Which are as follows:
• Oceans
• Land
• Cryosphere
• Life
This is the required right answer.