What is the action that allows one material to retain another material?

Answer: B — Absorption

The correct choice is absorption. Absorption refers to the process by which one substance permeates another, resulting in the incorporation of the absorbed material into the bulk of the absorbing material. For example, when a sponge soaks up water, the water molecules are absorbed and held within the sponge structure, demonstrating the characteristic of absorption. Adsorption, in contrast, involves a material adhering to the surface of another material. In this process, the molecules of the adsorbate adhere to the surface of the adsorbent without being absorbed into its bulk. Desorption is the reverse of adsorption; it involves the release of a substance that was previously absorbed or adsorbed. Retention typically refers to the ability to hold or contain, but does not specifically describe the mechanism of how one material takes in another. In the context of materials interacting with liquids or gases, absorption is the more precise term to describe the action of one material retaining another.