When a Company Uses an Accounts Receivable Subsidiary Ledger

When a company uses an accounts receivable subsidiary ledger,

A) it need not maintain an Accounts Receivable account in the general ledger.
B) credit sales transactions must be posted to the individual customers' accounts monthly.
C) when the amounts in the subsidiary ledger and the controlling account do not match,the accountant must find the error and correct it.
D) All of these choices.