What Is the Observed Distribution of the Shorter-Living Gamma-Ray Bursters

What is the observed distribution of the shorter-living gamma-ray bursters in the sky?

A) They are concentrated primarily along the plane of the Milky Way, indicating an origin in the Galaxy.
B) They are uniform over the entire sky, indicating an origin at "cosmological" distances.
C) They are clumpy but not coinciding with any known galaxy clusters, indicating an origin in a new kind of astronomical object.
D) They are clumpy, approximately coinciding with large clusters of galaxies such as the Coma cluster.