Dark matter has been postulated to explain
Select one:
a. the redshift that is observed for distant galaxies.
b. the need for the Cosmological Constant, which describes the
acceleration in the expansion of the Universe.
c. the presence of dark patches in the Milky Way, which prevents
us from seeing certain regions of the sky.
d. why matter in the outer edges of galaxies orbit the galactic
centre faster than predicted from accounting for the mass of the
luminous matter.
e. the unusually high number of standard candle supernova
explosions observed in the Universe, which proves that the Universe
is expanding.