A) The Ingram Civilian MAC 10 is from the Military Ingram version except it is a semi-automatic instead of having a selector switch that goes from semi-auto to full auto. Ingram is the original designer of both the MAC 10 and the 11.
Cobray is a copy (Clone).
Cobray is like buying a Uberti Cowboy handgun versus buying an Ingram which would be equivalent to a Colt handgun.
Although Cobray is a fine weapon it is not in anyway an Ingram and should never be confused or purchase as one. They look the same but are not. Ingram by the way is out of business and their MAC-10's are collectible in both 9mm and 45 ACP. Ingram can be converted from a 9mm to a 45 ACP and back and can also be converted to a full auto with silencer with no gunsmith needed.
The Ingram MAC-10 .....
45 ACP -
The Cobray Mac 10 .....