Which of the Following Is Most Likely to Be a Disadvantage

Which of the following is most likely to be a disadvantage for a retailer in developing customer loyalty through offering popular national brands?

A) The costs associated with offering popular national brands are very high.
B) There is often a huge reduction in the profit margin for the retailer.
C) Other competitors can purchase and sell the same popular products.
D) Training employees to operate the new product or service involves time and effort.
E) It leads to brand cannibalization.