Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. NIR Class 450 - The Class 450 is a type of diesel multiple unit (DMU) formerly used by Northern Ireland Railways. They were affectionately nicknamed 'Thumpers' and 'Castles' (Also known as the Castle Class) by rail enthusiasts.
Answer:
Mean Of Transportation