Which One of the Following Statements Is Correct

Which one of the following statements is correct?

A) Cash concentration accounts apply only to firms with geographically diverse manufacturing facilities.
B) Cash concentration accounts should improve the efficiency of a firm's cash management.
C) A firm with a lock-box system does not need a concentration account.
D) Firms generally need multiple concentration accounts.
E) Concentration accounts are not needed when a firm's disbursements are all done electronically.