Efforts to Relate Gamma-Ray Bursts with Specific Sources Has Had

Efforts to relate gamma-ray bursts with specific sources has had what results so far?

A) Gamma-ray bursters always occur in the depths of space, far from any galactic or other obvious source.
B) Gamma-ray bursters, including those observed in the Milky Way Galaxy, always occur in the centers of galaxies.
C) Gamma-ray bursters appear to occur in galaxies but not at the centers of galaxies.
D) Gamma-ray bursters occur in globular clusters, well away from the main regions in the host galaxy.