The folk art historian visited the deep interiors of the tribal communities to study the artists with unique dance patterns, symbolic expressions and exquisite postures
(A) with unique dance patterns, symbolic expressions and exquisite postures
(B) whose patterns of dances exhibited unique symbols and exquisite postures
© who danced uniquely, expressed symbolically and postured exquisitely
(D) with dance patterns that were unique, expressions that were symbolic and postures that were exquisite
(E) whose dances exhibited unique patterns, with symbolic expressions and exquisite postures.
'With' is incorrect usage as we are not sure who it refers to. It could be either the folks art historian or the artists. So A & D are out.
E is out because its wordy and not parallel.
Left with B & C.
Patterns of dances sounds awkward. Rather Dance patterns sounds better. Also C has a clear parallelism involved.
Hence IMO C is the right option.