Concept:A supermarket is a large retail store that sells mainly food and household items.
Its distinguishing feature is the type of goods it stocks.
Explanation:Supermarkets operate on high turnover and self-service.
They offer a wide variety and assortment of everyday consumer goods.
Unlike other large-scale retail outlets, their core items are mainly household goods and groceries.
Industrial goods are not typical supermarket products.
Post-delivery and single-line products do not describe a supermarket’s main selling feature.
Therefore, the unique distinguishing feature is that the items sold are mainly household goods.
Answer:A. mainly household goods