Answer: This is a matter of opinion but I think it is C
Step-by-step explanation:
By dark ages it means little happened, and so we can assume that it means that there was no advancements. Problems were not solved, so we can rule out D. There was no advancements, also ruling out A. B and C are extremely similar statements, but as there was little advancement I doubt that they failed to meet public demand, or B. Therefore, I believe that public interest was greatly diminished, giving us our answer of C.