The correct answer is Nitrogen.Bulbs are filled with chemically inactive gases like Nitrogen or Argon to prevent the oxidation of the tungsten filament used in the bulb.About Nitrogen:It is the chemical element with atomic number 7 and is denoted by the symbol (N).Nitrogen gas constitutes 78 % of the Earth's Air.Nitrogen is odorless, colorless, and generally considered an Inert Gas in Nature.Nitrogen was discovered by chemist and physician Daniel Rutherford in 1772.?Additional InformationHydrogen:The atomic number is 1 and is denoted by the symbol (H).It was discovered by Henry Cavendish.Carbon dioxide:The atomic number is 6 and is denoted by the symbol (CO2).It was discovered by Joseph Black.