What Was a Surprise to Astronomers When They Carefully Examined

What was a surprise to astronomers when they carefully examined Neptune with the Hubble Space Telescope in 1994?

A) the magnetic field of the planet had reversed (north was now south)
B) new elements and compounds were found in the upper atmosphere that had not been there before
C) the Great Dark Spot had disappeared
D) the wind speeds had slowed considerably
E) a large smiley-face had been constructed using dark clouds