How Do We Know the Expansion of the Universe Is

How do we know the expansion of the universe is accelerating?

A) We're really not that sure the expansion is accelerating; it's all just a theory.
B) White dwarf supernova in distant galaxies are fainter than they would be if the expansion were not accelerating.
C) We see more of the universe every night, as the observable universe grows in size.
D) The rotation curves of galaxies indicate the universe is speeding up.
E) Redshifts of distant galaxies are increasing with time, so when we repeat the measurements, the redshifts are larger.