The answer to your question is A, most likely.
The legend is that Newton discovered Gravity when he saw a falling apple while thinking about the forces of nature. Whatever really happened, Newton realized that some force must be acting on falling objects like apples because otherwise they would not start moving from rest.
The correct option is C.
Plate tectonic theory explains the structure of the earth's crust and the many phenomena that are associated with it. This theory enables the scientists to know that there are movements in the interior of the earth which are responsible for volcanic eruptions and earthquakes.
