Final answer:
Pointers are the type of dogs primarily used to upland game birds.
Step-by-step explanation:
The type of dogs primarily used to upland game birds are pointers. Pointers are specifically bred to locate and point to the location of game birds for hunters. They use their keen sense of smell and excellent sight to locate and indicate the presence of these birds. Retrievers, scent hounds, and sight hounds are not typically used for this purpose.