A.
In fact, most of the less developed areas are rich in natural resources, yet have great potentials for development.
B.
In fact, most of the less developed areas are rich in natural resources, and have great potentials for development.
C.
In fact, most of the less developed areas are rich in natural resources, but their development potential is very great.
D.
In fact, most of the less developed areas are rich in natural resources, as their development potential is very great.