Table:
0
A
B
C
D
E
1
Aircraft
Origin
Type
Versions
In service
2
Agusta A109
Italy
Recce helicopter
A109EOA-2
12
3
Agusta A129 Mangusta
Italy
Attack helicopter
CBT
56
4
Bell UH-1 Iroquois
United States
Transport helicopter
AB 205
42
5
Bell 212
United States
Transport helicopter
AB 212
39
6
Bell 412
United States
Transport helicopter
AB 412
31
7
NHI NH90
European Union
Transport helicopter
TTH
21
8
Boeing CH-47 Chinook
United States
Transport helicopter
CH-47C
14
9
Boeing CH-47 Chinook
United States
Transport helicopter
CH-47F
0
10
Dornier Do 228
Germany
Utility transport
Do 228-200
3
11
Piaggio P180 Avanti
Italy
Utility transport
P.180 M
3

Questions and formulas:
Question: Where is the origin of the tth version?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,D1="tth"),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E11,D2:D11="tth"),2))
Level: medium