Observationally,how Can We Tell the Difference Between a White-Dwarf Supernova

Observationally,how can we tell the difference between a white-dwarf supernova and a massive-star supernova?

A) A massive-star supernova is brighter than a white-dwarf supernova.
B) A massive-star supernova happens only once,while a white-dwarf supernova can repeat periodically.
C) The spectrum of a massive-star supernova shows prominent hydrogen lines,while the spectrum of a white-dwarf supernova does not.
D) The light of a white-dwarf supernova fades steadily,while the light of a massive-star supernova brightens for many weeks.
E) We cannot yet tell the difference between a massive-star supernova and a white-dwarf supernova.