Table:
0
A
B
C
D
E
F
1
District
Incumbent
Party
First elected
Result
Candidates
2
Alabama 1
Oscar Lee Gray
Democratic
1914
Retired Democratic hold
John McDuffie (D) Unopposed
3
Alabama 2
S. Hubert Dent, Jr.
Democratic
1908
Re-elected
S. Hubert Dent, Jr. (D) Unopposed
4
Alabama 3
Henry B. Steagall
Democratic
1914
Re-elected
Henry B. Steagall (D) Unopposed
5
Alabama 5
J. Thomas Heflin
Democratic
1904
Re-elected
J. Thomas Heflin (D) Unopposed
6
Alabama 6
William B. Oliver
Democratic
1914
Re-elected
William B. Oliver (D) Unopposed
7
Alabama 8
Edward B. Almon
Democratic
1914
Re-elected
Edward B. Almon (D) Unopposed

Questions and formulas:
Question: Who was the incumbent when ran william b. oliver (d) unopposed?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,F1="William B. Oliver (D) Unopposed"),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F7,F2:F7="William B. Oliver (D) Unopposed"),2))
Level: medium