Concept:A corrugated sheet metal must be flattened on a smooth, hard surface suitable for sheet metal work before it can be shaped into a funnel.Explanation:The tinman's anvil is a small anvil used by sheet metal workers, also called tinsmiths.It provides a firm, flat surface for hammering out corrugations and flattening sheet metal before further shaping such as making a funnel.The other tools are for bending or folding, not for flattening the sheet metal.Answer:B. tinman's anvil.