An AR lapping was detected in the last audit. You told the audit committee of the company that the company needs to improve its internal controls. The audit committee asked you what they should do to prevent AR lapping. You asked your assistant for input. He made four proposals:

(1)Write-offs of uncollectible accounts need to be approved by a supervisor independent of credit approval; (2) different people handle receiving cash and posting the accounts receivable ledger; (3) an independent supervisor should check and compare the daily cash summary with the sum of cash receipts journal entries; (4) an independent supervisor should verify dates of entry in the cash receipts journal with dates of cash prelist.

What would you say to him for each of these proposals?