Star Trek: Spoonheads Mystery Cache

Caching: The finder's frontier.  These are the voyages of the caching explorers.  Their life-long mission: to explore strange new towns, to seek out new caches and new hiding spots, to boldly go where no muggle has gone before.

This Star Trek Geoart is a tribute for Trekkies and non Trekkies all around. Answer the questions to find the final coordinates for each cache in the series. Cache is not at the posted coordinates. Enjoy!

Spoonheads

The Cardassians were a humanoid species from the Alpha Quadrant. They were native to the planet Cardassia Prime, capital world of the Cardassians. Known throughout the Alpha Quadrant for their ruthlessness, the Cardassians became one of the greatest enemies of the United Federation of Planets and Klingon Empire when they joined the Dominion in 2373. Their xenophobic attitude towards other species was well established throughout the quadrant after the Setlik III massacre during the Cardassian War, as well as when their atrocities during the Occupation of Bajor were revealed after their withdrawal in 2369. Externally, Cardassians were easily recognizable by each having light-gray skin, two thick vertical neck ridges that receded back to the crown of their head and an inverted tear-shaped crest in the center of the forehead. This crest has led to the derogatory nickname "spoonheads" used by other races.  -wikipedia

QUESTION FOR FINAL COORDINATES: The people of Cardassia belonged to what interplanetary empire? 

A. Cardassian Union - N39 21.937  W087 26.665

B. Cardassian States - N39 21.003  W087 26.230

C. Cardassian Empire - N39 21.125  W087 26.963

D. Cardassian United - N39 21.739  W087 26.789