The energy in a firecracker is completely chemical energy, in the gunpowder
or whatever else it's loaded with. When that powder burns, the smoke and hot
gas creates high pressure inside the can, which eventually blows the can open,
blowing out all the little burning grains of powder, and sending a shock wave out
through the surrounding air to make the 'POP'. So you have the chemical energy
released as heat, kinetic energy of all the fragments that fly out, and electromagnetic
energy of the heat and the visible light. That looks like Choice-'D'.
