Potassium-Argon and Argon-Argon Dating Techniques Are Used on

Potassium-argon and argon-argon dating techniques are used on

A) some minerals that form in igneous and metamorphic rocks.
B) igneous, metamorphic, and even in a few sedimentary rocks older than about 10 million years.
C) objects of biological origin, such as bones, teeth, and pieces of wood.
D) reef-building corals and certain other fossils with these elements within them.