Step 1: Comprehend the solvent extraction milling procedure. This method focuses on eliminating the oil-abundant bran layer from brown rice. Here, "polishing" signifies the bran layer's removal, and solvent use denotes an oil extraction technique.
Step 2: Determine the typical solvent for extracting edible oil. Hexane is the predominant solvent employed in the food sector for extracting oils from plants like soybeans, canola, and rice bran. It effectively dissolves oils, possesses a low boiling point for simple post-extraction removal, and is comparatively inexpensive. The other listed solvents are not generally used for food oil extraction due to concerns regarding safety, cost, or effectiveness.