Which of the following are true with respect to accounts receivables (select all that apply):

A) As a best practice, accounts receivables should be stated at net realizable value.

B) The gold standard of testing accounts receivable for occurrence is by using both positive and negative confirmations.

C) An internal control that management may put in place to ensure that all accounts receivable exist at period end is to review customers sale order.

D). Sending negative confirmations to a clients customers at year-end is an appropriate substantive test even when the response is low.