DEC advertises that it helped to create "the world's first expert system routinely used in an industrial environment," called XCON or:

Solution(By Examveda Team)

DEC (Digital Equipment Corporation) advertised that it aided in the development of "the world's first expert system routinely used in an industrial environment," known as XCON. XCON was developed by researchers at Carnegie Mellon University in the 1970s to configure orders for DEC's VAX computers.
Option A: PDP-11 and Option B: Rl are not directly associated with XCON or the development of expert systems.
Option D: MAGNOM is not relevant to the creation of XCON.
Therefore, the correct choice regarding the system created with DEC's help is Option C: VAX.