Many Unix shortcuts originally use the Meta key as a prefix, and for keyboards without such a key, they usually have an Alt key or an Esc key as a workaround, that is, the Alt key and the Esc key are almost interchangeable in key combinations. As for the Option key, you can find the Option key only from a magic keyboard by Apple, and while sometimes used as Alt key, the key almost always has different behaviours with Mac OS native programs.
