With respect to the prepare-off of an uncollectible account receivable against the allowance for bad debts, a sound system of internal control would require:
A. the prepare-off be approved by two employees.
B. an investigation of why credit was extended to this customer in the first place.
C. a lawsuit to be initiated to recover the uncollectible amount.
D. the prepare-off to be made within six months after the date of sale.