Answer:
C.This area was seen as undesirable by the Romans.
D. Mountains made this region difficult to access.
Explanation:
Some of the areas between Spain and Gaul were part of the Roman Empire way for many years before the 107 CE. However, some factors made it less attractive and welcoming to be part of the Roman Empire. There was also difficulty in gaining access to some areas between the territories due to high mountains. The appropriate options are C and D.