Question: The Audi RS4 quattro is the top tier and highest performing version of some specific generations of the Audi A4 range of automobiles, it slots distinctly above which high performance variant of Audi's compact executive car A4, and was the original Audi S4, built from 1991 until 1994?
Sentence (from "Audi S4"): The Audi S4 is the high performance variant of Audi's compact executive car A4.
Relevant evidence: Yes