Parmenides, Zeno, and Melissus: The Eleatics – Lecture 6 (History of Philosophy)

What is Parmenides' core thesis, stated in one line?

1. A.Everything is becoming; nothing truly is.
2. B.What is is, and what is not is not.
3. C.All is one stuff, and that stuff is fire.
4. D.Number is the principle of all things.