I always figured that they thought it would be nice to go along with the “Colt Automatic Pistol” and the “Colt Automatic Shotgun.” None of which were actually designed by Colt.
Technically, both “Automatic Rifle” and “ARmalite” are correct answers. “Assault Rifle” is not. :P
The ARmalite became the Colt Automatic Rifle.
Therefore, the correct answer is dependent on what time period is being referenced.