So, going through reddit I come across something really odd.
“The second disk of his Black Ops II retail copy is Mass Effect.”
Now I had to verify this proclamation, so I searched the net and seems it happened to a limited amount of people, but it is true.
No word as to how this occurred but this issue seems to only affect the PC version of Call of Duty: Black Ops II. Some have investigated the second disk and has noted they are in fact files titled "Mass Effect".
Since Call of Duty: Black Ops II two uses steam , players should use the serial key and download the game from the steam service, this will bypass the disc issue.