Table:
0
A
B
C
D
E
F
1
District
Incumbent
Party
First elected
Result
Candidates
2
Alabama 1
John McDuffie
Democratic
1918
Re-elected
John McDuffie (D) 84.0% Aubrey Boyles (R) 16.0%
3
Alabama 2
J. Lister Hill
Democratic
1923
Re-elected
J. Lister Hill (D) Unopposed
4
Alabama 4
Lamar Jeffers
Democratic
1921
Re-elected
Lamar Jeffers (D) 68.1% Omar H. Reynolds (R) 31.9%
5
Alabama 6
William B. Oliver
Democratic
1914
Re-elected
William B. Oliver (D) 99.0% C. M. Ayers (R) 1.0%
6
Alabama 8
Edward B. Almon
Democratic
1914
Re-elected
Edward B. Almon (D) 90.1% Robert M. Sims (R) 9.9%

Questions and formulas:
Question: When was incumbent William B. Oliver first elected?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,B1="William B. Oliver"),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F6,B2:B6="William B. Oliver"),4))
Level: medium