How Did Supernova 1987A Demonstrate That New Elements Are Made

How did Supernova 1987A demonstrate that new elements are made in supernova explosions?

A) spectra of the supernova light revealed elements that have never been found in Earth or the stars
B) the neutrinos observed from the supernova could only be produced through radioactive decay of heavy elements
C) a tank with 8000 tons of pure water under Lake Erie detected gamma rays from new elements
D) a pulsar with new elements in it was found using radio telescopes in England
E) the light output was kept at high levels by the energy released from radioactive elements that decay very quickly; these must have been made by the supernova