Question: 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. PRR D1 - The Pennsylvania Railroad's steam locomotive class D1 (formerly Class A pre-1895) comprised thirteen 4-4-0 locomotives for express passenger service constructed at the railroad's own Altoona Works during 18681872.
Answer:
Mean Of Transportation