When was the sixth game in the original Mega Man series released in the U.S.?
1994
1987
1987
1987
1987
1987
1987
1987
1987
1986
1991
1987
1986
1991
1987
1986
1991
1990
1987
1986
1991
1990
1987
1986
1991
1990
Mega Man 6
1987
1986
1992
1991
1990
1987
1986
1992
1991
1990
1987
1986
1992
1991
1990
1987
1986
1992
1991
1990
1987
1986
1992
1991
1990
Mega Man 2
1983
1987
1986
1992
Mega Man 3
1991
1990
1983
1989
1987
1986
1992
1991
1990
1983
1989
1988
1987
1985
1995
1986
1992
1991
1990
1983
1989
1988
1985
1994
1995
1986
1992
1991
1990
November 23, 1987
November 21, 1987
1983
November 17, 1987
1989
1988
1985
1994
1995
1986
1992
Mega Man 7
November 9, 1987
1991
1990
1983
1989
1988
Mega Man 4
1985
1994
1995
1986
1992
1991
1990
1983
1989
1988
1985
1994
1995
1986
1992
November 13, 1987
1991
November 28, 1987
1990
1983
1989
1988
1993
1985
Mega Man 5
1994
1995
1986
1992
November 21, 1991
1991
November 11, 1987
1990
1983
1989
1988
1993
Mega Man IV
1985
1994
1995
1986
1992
1996
1991
November 21, 1986
1990
November 23, 1987
November 21, 1987
1983
November 15, 1987
November 17, 1987
1989
November 21, 1991
1988
1993
1985
1994
1984
1995
1986
1992
1996
November 9, 1987
1991
1990
1983
1989
1988
November 21, 1986
1993
1985
1994
1984
1995
November 21, 1992
1992
1996
November 13, 1991
1990
1982
1983
1989
1988
1993
1985
1994
1984
1995
November 11, 1991
1992
November 13, 1987
1991.
November 21, 1991
1996