Answer the following 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. HMS K9 -  HMS K9 was a K class submarine built by Vickers Barrow-in-Furness. K9 was laid down on 28 June 1915. She was commissioned on 9 May 1917. In 1921 K9 was placed in reserve. K9 was sold in Charlestown on 23 July 1926.
Answer:
Mean Of Transportation