Suppose You Read Somewhere That 10 Percent of the Matter

Multiple Choice

Suppose you read somewhere that 10 percent of the matter in the Milky Way is in the form of dust grains.Should you be surprised? If so,why?

A) There is nothing surprising about 10 percent of the matter being dust grains because dust grains are the material from which stars are born.
B) Given how easily dust grains form,10 percent is a surprisingly low fraction of material to be in that form.
C) Ten percent is surprisingly high because dust grains can form only at low temperatures.
D) The 10 percent figure cannot be correct,because dust grains are solid but only about 2 percent of the matter in our galaxy is made of anything besides hydrogen and helium.