Concept:Supermarkets are large-scale self-service stores that primarily sell household and everyday consumer goods.
Explanation:Supermarkets stock a wide variety of products.
These products include food, cleaning supplies, toiletries, and other household items.
They do not specialise in a single line of products.
They do not sell mainly industrial goods.
They do not deliver goods by post as a main feature.
Selling a broad range of mainly household goods is what makes supermarkets different from other large-scale retail outlets.
Answer:A. mainly household goods