Hey there!
I believe answer is B2 or Beta 2
Answer:
Either (1.) Fossils or (2) Radiometric dating.
Explanation:
Fossils are an obvious answer to this, but radiometric dating is the method most scientists use to find the age of rocks. Radioactive isotopes break down predictably, so the farther along this process is, the older the rock is.
Land takes up mass and so does the water
The carbon cycle - CO2 is fixed into biomolecules.