The text states that luminous matter in the Milky Way seems to be much like the tip of an iceberg. This refers to the idea that
Answer
A) luminous matter emits white light, much like the light reflected from icebergs.
B) black holes are much more interesting than ordinary stars that give off light.
C) dark matter represents much more mass and extends much further from the galactic center than the visible stars of the Milky Way.
D) the luminous matter of the Milky Way is essentially floating on the surface of a great sea of dark matter.