Tokyo Metro 06 series -  The Tokyo Metro 06 series (東京地下鉄06系 Tōkyō Chikatetsu 06-kei) is an electric multiple unit operated by Tokyo Metro on the Tokyo Metro Chiyoda Line in Tokyo Japan. One 10-car set was delivered in December 1992 and entered service in March 1993. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
A:
Mean Of Transportation