$15,$ Which of the options below can NOT be considered as advantages retailers ca n gain from creating offline and online integrations? $$

A$.$ Retailers gain an increased amount of data about customers and consumer preferences $$

B$,$ Customers can experience an increased value of loyalty programs as offline behavior is reflected in online offerings, and vice$-$versa.

C$.$ The companies need to invest in training and upskilling employees to help them adapt to their new responsibilities and new employees have to be hired. $$

D$.$ Logistic needs deriving from online channels can be combined with the existing offline infrastructure to reduce warehouse costs.