Type 1a supernovae, caused by the detonation of matter accreted onto

Type 1a supernovae, caused by the detonation of matter accreted onto white dwarf stars, explode with a highly predictable brightness. Since the brightness of these explosions fades over distance in a highly predictable way, scientists have long used images measuring the brightness of type 1a supernovae to determine the distance to distant galaxies.

Which of the following discoveries, if true, would most jeopardize scientists' reliance on images of type 1a supernovae as tools for measuring distances to distant galaxies?

A. Models explaining the causes of type 1a supernovae are altered to include an updated understanding of the role played by carbon fusion.
B. Type 2 supernovae are discovered to be even more dramatically variable in their brightness than previously thought.
C. Large clouds of interstellar dust and ionized hydrogen can absorb the light emitted by type 1a supernovae.
D. Some supernovae exhibit very unusual spectral classifications and changes in brightness, and do not fit into the existing categories.
E. A new telescope is able to measure the brightness of several thousand type 1a supernovae with an unprecedented level of precision.