One Piece of Evidence for the Existence of Dark Matter

Multiple Choice

One piece of evidence for the existence of dark matter is the

A) absence of interstellar materials (gas and dust) from elliptical galaxies.
B) low count of neutrinos emitted from the center of the Sun.
C) scarcity of dwarf ellipticals in the Local Group of galaxies.
D) discrepancy between observed mass and the required gravitational binding in rich clusters of galaxies.