Question: Which song did Metallica release in 1991 from their fifth album that is one of their most well known?
Sentence (from "Metallica (album)"): "Metallica" produced five singles that are considered to be among the band's best-known songs, which include "Enter Sandman", "The Unforgiven", "Nothing Else Matters", "Wherever I May Roam", and "Sad but True". "
Relevant evidence: Yes