DSM-5 Includes Gambling Disorder as an Addictive Disorder, Along with Substance

DSM-5 includes gambling disorder as an addictive disorder, along with substance use disorders. This inclusion is:

A) unique; gambling disorder is the only disorder in the category that doesn't involve a substance.
B) unusual; gambling disorder joins computer gaming disorder as the second disorder in the category that doesn't involve a substance.
C) unusual; gambling disorder and computer gaming disorder both were added as non-substance disorders in the category.
D) common; there presently are seven other disorders in the category that don't involve a substance.