Test and analysis: analysis options, the goods described in item C do not match the description of the stem, item D does not involve the types of goods bought and sold in the market, item A refers to "river goods", which should refer to some aquatic products, and item B refers to the rich. This sentence means that the son and brother of the rich are near the East Street of Jinshi (playing), and Jinshi here refers to the West City of Chang 'an, so the answer is B.