At the end of an experiment, the product is a mixture of the starting material, which is benzoic acid and the product, which is benzaldehyde, both of which are dissolved in diethyl ether. the reaction mixture is best separated by

a. extraction with a solution of hydrochloric acid, separating the layers, followed by drying and evaporating the organic layer.

b. extraction with a solution of sodium bicarbonate, separating the layers, followed by drying and evaporating the organic layer.

c. drying and evaporating the organic layer.

d. extraction with a solution of sodium bicarbonate, separating the layers, add diethyl ether to the aqueous layer, extracting with a solution of hydrochloric acid, filtering and recrystallization the solid product.