Unlike other retail outlets, where items are purchased in any number of units the customer wants, in super - markets items are grouped in bulk packages. This bulk buying offers savings to the customer. The option to buy at wholesale prices by buying in bulk makes super - markets a practical choice for budget - conscious consumers.
Which of the following is an assumption necessary to the author’s argument?

Super - markets often have great buying power and lower overhead costs, so they can offer a greater variety of products than regular retail outlets.

Super - markets are often more conveniently located and have better parking facilities.

The emergence of super- markets has caused many small retail stores to close down and thus eliminate competition.

It is economically wise to buy single items since bulk passages seldom offer significant savings.

The financial savings from purchasing bulk packages may outweigh the inconvenience of being unable to purchase in any number of units that suits the customers’ needs.