Course for chariot races

Answer: Option C

One word substitute is Hippodrome.

Sanatorium: an establishment for the medical treatment of people who are convalescing or have a chronic illness.
Hangar: a large building with an extensive floor area, typically for housing aircraft.
Hippodrome: a stadium for chariot or horse races.
Arena: a level area surrounded by seating, in which sports, entertainments, and other public events are held.