Task: Text Categorization
Input (English): Context: The THK-5 was a twin-engine aircraft developed in Turkey in 1945 as an air ambulance. It was a conventional low-wing cantilever monoplane of wooden construction throughout. The main units of the tailwheel undercarriage retracted into the wing-mounted engine nacelles and the THK-5 could carry two stretcher cases plus a medical attendant.
Question: The document can be classified to which topic? 
Options: 1)NaturalPlace, 2)MeanOfTransportation, 3)OfficeHolder, 4)Artist
Output (English): 2