Which of the following is true about processes that shape the Earth?
A.
All processes that shape the Earth begin and end within a person's lifetime.
B.
Although there are many different processes that shape the Earth, none of the processes can be observed by humans.
C.
Only one process shapes the Earth in a way that humans can notice.
D.
Some processes that shape the Earth are happening so slowly they cannot be easily detected in a human's lifetime.