If an account is collected after having been previously written off:
a. the allowance account should be debited
b. only the control account needs to be credited
c. both income statement and balance sheet accounts will be affeted
d. there will be both a debit and a credit to accounts receivable

There will be both a debit and a credit to accounts receivables ( D )

Explanation:

The accounts receivable should be debited and credited because when an account has been written off it is considered a bad debit ( account that is lost to debt or cannot be collected or retrieved  by the company from the debtor ) and Bad debits are debited in the accounts receivables.

When an account written off ( bad debit ) is collected by the company the accounts receivables should be credited in order to offset the bad debit that was previously debited in the accounts receivables of the company. this is necessary so that the collected account will reflect on the Revenue of the  company.