The correct explanation for the placement of an agricultural product within von Thünen’s agricultural land-use model is:
Tomatoes are grown closest to the market because they spoil quicker than beef or grain.
In von Thünen's model, perishable goods are located closer to the market to minimize transportation costs and reduce spoilage. Tomatoes, being perishable, are placed near the market, whereas less perishable items like grains and beef are placed further away.