Answer : The question is to write the elements alphabetically and seperating them with commas.
So in this case for your question of Fireworks , K

,
The answer will be
K, N, O.
You have to just differentiate the elements and write them according to the alphabetical order.
I would say B but I am not sure so sorry if it is wrong!!
Ice caps would float therefore providing insulation for aquatic life and ensuring they do not freeze due to the cool temperature.
answer
When an electron temporarily occupies an energy state greater than its ground state, it is in an excited state. An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light, or collides with a nearby atom or particle