Which of the following is the symbol of the element whose filaments are used in bulbs?

W is the symbol of the tungsten filaments used in bulbs.

A symbol is a short way to represent anything. A symbol of any element is a letter that represents an atom of an element. The symbol of an element is the ‘first letter’ or the ‘first letter and another word’ of the English name or Latin name of the element.

Tungsten  is the element used in making the filament of a bulb.

The symbol of tungsten is W. The symbol "W" is derived from the element's earlier name, "wolfram." The name "wolfram" was derived from the German term "wolf rahm," which means "wolf's froth." This name was given to the mineral tungstenite, which contains tungsten.

As a result of its high melting point and lack of oxidation, tungsten (W) is used in electric bulbs.