When did Metallica put out their fourth album?
1988
1991
1991
1991
1991
1991
1991
1991
1991
1991
1991
1991
1991
1992
1991
1992
1991
1983
1992
1991
1983
1992
1991
1988
1983
1992
1991
1988
1983
1992
1990
1991
1988
1983
1992
1990
1991
1988
1983
1992
1990
1991
1986
1993
1988
2001
1983
1992
1990
1986
1993
1989
1988
2001
1983
1992
1990
1995
1986
1993
1989
1988
2001
1983
1992
1990
1995
1986
1993
1989
1988
2001
1984
1983
1992
1985
1990
1995
1986
1993
1989
1988
1998
2001
1984
1983
1992
1985
1990
1995
1986
1993
1989
1988
1998
2001
2000
1984
1983
1992
2003
1985
1990
1995
1986
1996
1993
1989
1988
1998
1991.
2001
2000
1984
1983
1992
2003
1985
1990
1995
1986
1996
1993
1989
1988
1998
2001
2000
1984
1983
1992
2003
1985
1990
2002
1995
1986
1996
1993
1989
1988
1997
1998
2001
2000
1984
1983
1992
2003
1985
1990
2002
1995
1986
1996
1993
1989
1988
1997
1998
2001
2000
1984
1983
1992
2003
1985
1990
2006
2002
1995
1986
1996
1993
1989
1988
1997
1998
2001
2000
1984
1983
1992
2003
1985
1990
2006
2002
1995
1986
1996
1993
1989
1988
1987
1997
1998
1991.
August 1991
August 1991
1983.