Hi Frankie! You have to actually tell us your question, this doesn't give us much information about what you need! and I also I believe this is under math, not history!
Thucydides viewed war and politics as being inherently intertwined, since he believed that war was simply the means that humans resorted to when political discussions failed.
The best explanation why the area between Spain and Gaul was not part of the Roman empire until that later period was a culmination from both undesireability and difficulty in accessing this region due to its mountaineous nature. So I would wager the answer being both C and D - undesireability and difficulty in access.
