Which is the real chair and why?

This was the most heated debate of my college experience so far. Your thoughts?

In case you can't read the third, it's the definition of a chair: A seat with a back, and often arms, usually for one person; a seat of office or authority, or the office itself; the person occupying the seat or office, esp. the chairman of a meeting; a sedan-chair; a chaiset; a metal block or clutch to support and secure a rail in a railroad.