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.
A mustang is a kind of horse and a kind of car
Somatization is associated with a form of mental illness that causes one or more bodily symptoms, including pain.
<span><span>Rene Descartes is known
for the Cartesian coordinate system and the belief that mathematics can explain
all of nature. He is the father of analytical geometry (by using algebra
to describe geometry). We often relate to his Cartesian coordinate system in
maps or graphs to know how far along and how far up it is. </span>He
was also the one who invented the representation of unknowns in
mathematical equations by using x, y, and z, and then the
knowns by using a, b, and c<span>.</span></span>