The Detection of Neutrinos from SN 1987A Occurred 3 Hours

Multiple Choice

The detection of neutrinos from SN 1987A occurred 3 hours before the detection of the burst of visible light. What caused this time lag?

A) Neutrinos travel faster in vacuum than light does.
B) The space between the supernova and Earth is not a perfect vacuum but is filled with very rarefied gas and dust, which impedes the passage of light (very slightly) but not of neutrinos.
C) The neutrinos and the light were produced at the same time, but the light bounced back and forth between the core and the outer layers several times before these layers expanded to the point that they became transparent.
D) The neutrinos were produced earlier (when the core collapsed) , and the light was produced 3 hours later (when the shock wave reached the outer layers) .