If you could look inside the sun today, you’d find that its core contains a much higher proportion of helium and a lower proportion of hydrogen than it did when the sun was first born.

hurricanes form in warm water

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.

you need to have a picture of the atom that way we can answer it