One of the most common methods to date volcanic rocks uses potassium (radioactive parent) and argon (stable daughter). Potassium is an element found in many minerals and rocks, and it normally has an atomic mass of 39.
I think it is B and A sorry if wrong
They generally test for infections, changes in body tissue and organs, and they test for the presence of chemicals such as drugs or poisons.
In glacial erosion by abrasion, a glacier loosens and lifts blocks of rock as it flows over the surface.
Hope helps!-Aparri