____ is the withdrawal of desired compounds from plant material by the use of the selected solvents in which the desired compounds are soluble.

• A. Percolation
• B. Maceration
• C. Diffusion
• D. Extraction

Answer: (D)

The process described is extraction. It refers to pulling out the desired constituents from plant material by dissolving them in a solvent in which they are soluble, so they move from the solid plant matrix into the liquid phase based on solubility and affinity.

Maceration and percolation are methods to accomplish extraction—maceration involves soaking the plant material in solvent to allow solutes to diffuse out, typically at room temperature; percolation uses solvent passing through a bed of material to continuously dissolve compounds. Diffusion is the mechanism that drives movement of molecules from higher concentration inside the plant into the solvent, aiding extraction, but the term defined by the statement is the overall extraction process.