When the Retail Sector Is Very Concentrated

When the retail sector is very concentrated:

A) it is more expensive for a firm to make contact with each individual retailer.
B) it makes sense for a firm to deal directly with retailers, cutting out wholesalers.
C) a relatively large sales force is required to deal with the retail sector.
D) the channels of distribution tend to be long.
E) the growth of wholesalers is promoted.