Q:Christina Crain Unit - The Christina Melton Crain Unit (formerly the Gatesville Unit) is a Texas Department of Criminal Justice prison for females in Gatesville Texas. The prison is along Texas State Highway 36 3 miles (4.8 km) north of central Gatesville. The unit with about 1317 square feet (122.4 m2) of space is co-located with the Hilltop Unit the Dr. Lane Murray Unit and the Linda Woodman Unit. The unit's regular program houses around 1500 women and it is one of Texas's main prisons for women. 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:
Building