Gold, silver and sodium are the name of the elements which does not match to their abbreviation. It is because those names are comes from other language. For example, the symbol of sodium is Na which comes from Natrium that is a Latin word. The symbol of gold is Au which comes from Aurum that is also a Latin word. The symbol of silver is Ag which comes from a Latin word i. e. Argentum.
I believe the correct answer would be the last option. When an electrons moves from an excited state to the ground state, it would release energy. An electron in the excited state would mean that it contains high kinetic energy so to move to a lower state some of these energy should be released.
