Table:
0
A
B
C
D
E
1
Week
Date
Opponent
Result
TV Time
2
1
September 7, 1998
at Denver Broncos
L 27–21
ABC 9:00pm
3
2
September 13, 1998
Indianapolis Colts
W 29–6
ESPN 8:15pm
4
3
September 20, 1998
Tennessee Oilers
W 27–16
CBS 1:00pm
5
4
Bye
Bye
Bye
Bye
6
5
October 4, 1998
at New Orleans Saints
W 30–27
CBS 1:00pm
7
6
October 11, 1998
Kansas City Chiefs
W 40–10
CBS 1:00pm
8
7
October 19, 1998
New York Jets
L 24–14
ABC 9:00pm
9
8
October 25, 1998
at Miami Dolphins
L 12–9
CBS 1:00pm
10
9
November 1, 1998
at Indianapolis Colts
W 21–16
CBS 1:00pm
11
10
November 8, 1998
Atlanta Falcons
L 41–10
FOX 1:00pm
12
11
November 15, 1998
at Buffalo Bills
L 13–10
CBS 1:00pm
13
12
November 23, 1998
Miami Dolphins
W 26–23
ABC 9:00pm
14
13
November 29, 1998
Buffalo Bills
W 25–21
CBS 4:15pm
15
14
December 6, 1998
at Pittsburgh Steelers
W 23–9
CBS 4:15pm
16
15
December 13, 1998
at St. Louis Rams
L 32–18
CBS 1:00pm
17
16
December 20, 1998
San Francisco 49ers
W 24–21
FOX 1:00pm
18
17
December 27, 1998
at New York Jets
L 31–10
CBS 1:00pm

Questions and formulas:
Question: Which opponent was playing on December 20, 1998?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,B1="december 20, 1998"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E18,B2:B18="december 20, 1998"),3))
Level: medium