Is the self$-$service checkout function consistent with Walmart's competitive strategy?

Question $9$ options:

A$)$

No$,$ its basic function is to improve customer service by allowing the customer to check out their own groceries and have control of their bagging.

B$)$

No$,$ its basic function is to save cost by allowing one front$-$end employee to service multiple checkout lanes.

C$)$

Yes, its basic function is to save cost by allowing one front$-$end employee to service multiple checkout lanes.

D$)$

Yes, its basic function is to improve customer service by allowing the customer to check out their own groceries and have control of their bagging.