The 2009 Impact Site near the South Pole of Jupiter's

The 2009 impact site near the south pole of Jupiter's atmosphere was noticeably different from the 1994 impacts.How?

A) The 2009 site was much larger, indicating a more massive impactor.
B) The 2009 site was surrounded by a halo of small impacts, indicating an impact by an asteroid rather than a comet.
C) The 2009 site was not surrounded by a halo of small impacts, thus indicating an impact by an asteroid rather than a comet.
D) The colors that developed at this site were different from those of the earlier impacts because of differences in temperature and composition of Jupiter's atmosphere near the poles.