Which internal control$($s$)$ would you recommend to prevent the following situations from occurring? LO $11-2$

a$.$ Authorization of a credit memo for a customer's account $($on receivables$)$ when the goods were never actually returned.

b$.$ Theft of funds by the cashier, who cashed several checks and did not record their receipt.

c$.$ Inventory stolen by receiving dock personnel. The receiving clerk claimed the inventory was sent to the warehouse,

but the warehouse clerk did not record properly.

d$.$ Writing off a customer's accounts receivable balances as uncollectible in order to conceal the theft of subsequent cash

collections.

e$.$ Billing customers for the quantity ordered when the quantity shipped was actually less due to back$-$ordering of some

items.