Which of the following is true about elements in the Earth system?
A.
The Earth system essentially contains a fixed amount of chemical elements that cannot cycle through different reservoirs on Earth.
B.
The total amount of chemical elements on Earth is constantly increasing as the Earth system creates elements within its core.
C.
The total amount of chemical elements on Earth is constantly decreasing as plants and animals take in nutrients.
D.
The Earth system essentially contains a fixed amount of chemical elements that cycle continuously throughout the system.