Which one of the following is the best example of desiccant?

A desiccant is a hygroscopic substance used to induce or sustain a state of dryness in its vicinity by absorbing or adsorbing moisture. Silica gel is the most popular and widely used desiccant, consisting of a porous, granular form of silicon dioxide with a high surface area that effectively adsorbs water molecules. It is commonly encountered in pre-packaged forms to maintain the crispness of food or protect sensitive goods during transport [2]. While sodium chloride and sodium carbonate exhibit hygroscopic properties—meaning they can attract water—they are less effective as general-purpose desiccants compared to silica gel [1][4]. Sodium chloride can become damp and cakey, and sodium carbonate is primarily used in industrial processes like glass and soap manufacturing rather than as a primary drying agent [1]. Polystyrene is a synthetic polymer and does not possess the hygroscopic properties required to function as a desiccant.

Sources

1. [2] https://en.wikipedia.org/wiki/Desiccant
2. [1] https://en.wikipedia.org/wiki/Hygroscopy
3. [4] https://par.nsf.gov/servlets/purl/10027329