What Makes White-Dwarf Supernovae Good Standard Candles

Multiple Choice

What makes white-dwarf supernovae good standard candles?

A) They are very bright,so they can be used to determine the distances to galaxies billions of light-years away.
B) They should all have approximately the same luminosity.
C) They occur so frequently that we can use them to measure the distances to virtually all galaxies.
D) We have had several occur close to us in the Milky Way,so we have been able to determine their luminosities very accurately.
E) both A and B