Table:
text: Murder, She Wrote
U.S. television ratings
Television ratings
Season Episodes Season_premiere Season_finale TV_season Rank_ Households_millions
1 22 September 30, 1984 April 21, 1985 1984/85 #8 17.06
2 22 September 29, 1985 May 18, 1986 1985/86 #3 21.73
3 22 September 28, 1986 May 10, 1987 1986/87 #4 22.19
4 22 September 20, 1987 May 8, 1988 1987/88 #9 17.89
5 22 October 23, 1988 May 21, 1989 1988/89 #8 17.98
6 22 September 24, 1989 May 20, 1990 1989/90 #13 16.30
7 22 September 16, 1990 May 12, 1991 1990/91 #12 15.26
8 22 September 15, 1991 May 17, 1992 1991/92 #8 15.56
9 22 September 20, 1992 May 16, 1993 1992/93 #5 16.47

Question: From the list of murders she wrote season, which season had a season finale on May 21, 1989 and was viewed by 17.98 million households?