Observationally, How Can We Tell the Difference Between a White-

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

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