Table:
0
A
B
C
D
E
F
1
Week
Date
Opponent
Result
Venue
Attendance
2
1
1990-09-09
San Diego Chargers
W 17–14
Texas Stadium
48,063
3
2
1990-09-16
New York Giants
L 28–7
Texas Stadium
61,090
4
3
1990-09-23
at Washington Redskins
L 19–15
Robert F. Kennedy Memorial Stadium
53,804
5
4
1990-09-30
at New York Giants
L 31–17
Giants Stadium
75,923
6
5
1990-10-07
Tampa Bay Buccaneers
W 14–10
Texas Stadium
60,076
7
6
1990-10-14
at Phoenix Cardinals
L 20–3
Sun Devil Stadium
45,235
8
7
1990-10-21
at Tampa Bay Buccaneers
W 17–13
Tampa Stadium
68,315
9
8
1990-10-28
Philadelphia Eagles
L 21–20
Texas Stadium
62,605
10
9
1990-11-04
at New York Jets
L 24–9
The Meadowlands
68,086
11
10
1990-11-11
San Francisco 49ers
L 24–6
Texas Stadium
62,966
12
11
1990-11-18
at Los Angeles Rams
W 24–21
Anaheim Stadium
58,589
13
12
1990-11-22
Washington Redskins
W 27–17
Texas Stadium
60,355
14
13
1990-12-02
New Orleans Saints
W 17–13
Texas Stadium
60,087
15
14
Bye
Bye
Bye
Bye
Bye
16
15
1990-12-16
Phoenix Cardinals
W 41–10
Texas Stadium
60,190
17
16
1990-12-23
at Philadelphia Eagles
L 17–3
Veterans Stadium
63,895
18
17
1990-12-30
at Atlanta Falcons
L 26–7
Atlanta-Fulton County Stadium
50,097

Questions and formulas:
Question: What team was the opponent on 1990-10-21?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,B1="1990-10-21"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F18,B2:B18="1990-10-21"),3))
Level: medium