Where does the name OREO come from?

OREO was registered as a Nabisco trademark in 1913, but where does the name come from? The exact origins of the name OREO are uncertain but there are a few theories:

1. OREO was named by taking the "RE" out of cream and sandwiching it between the two "O"s from chocolate - just like the cookie.
    
2. The name comes from the word "OR" (meaning gold in French) - a colour used on early packaging designs.
    
3. OREO comes from the Greek word "OREO" which means mountain or hill. When the cookies were first manufacture, it was shaped like a baseball mound - hence the name OREO.
    
4. Some say the name came about because it just seemed like a nice, melodic combination of sounds with just a few catchy letters and it was easy to pronounce.