Changes in the composition of the light of a supernova —an exploding star— reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas.(a) reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas(b) reveals not only what chemical elements are in the explosion but also the speed at which the outer layers of stellar gas are expanding(c) not only reveal the chemical elements in the explosion but also the speed of the expanding outer layers of stellar gas(d) not only reveal what chemical elements are in the explosion but also the speed of the outer layers of stellar gas when they are expanding(e) reveal not only the chemical elements in the explosion but also the speed at which the outer layers of stellar gas are expanding