<span>Electric
current passes through a filament of an incandescent bulb, thereby increasing
it temperature. When current flows, it contains electrons through the filament
to produce light. The answer is c. Typically, incandescent light bulb consists
of a glass enclosure that contains tungsten filament. The glass enclosure contains
either a vacuum or an inert gas that serves as the filament protection from
evaporating. Incandescent light bulbs contain a stem attached at to its base to
allow the electrical contacts to run through the envelope without gas or air
leaks</span>
