A debit balance in the allowance account may exist before recognizing estimated uncollectibles for the period because

a. firms sometimes write off specific customers' accounts during an accounting period as the firm identifies the specific customers whose accounts have become uncollectible.
b. firms generally wait until the end of the accounting period to recognize bad debt expense for the period.
c. the account will always have a credit balance after recognizing the provision for estimated uncollectibles for the period.
d. all of the above.
e. none of the above.

D