Which method records uncollectible accounts expense only when an amount is actually known to be uncollectible?

The direct write-off method is the correct choice because it matches the recognition of uncollectible accounts expense with the specific moment when an account is definitively identified as uncollectible. Under this method, no estimation is made for uncollectible accounts in advance; instead, the expense is recorded only when a specific account has been determined to be uncollectible, typically when all collection efforts have been exhausted, and therefore, there is certainty that the debt will not be collected.

This stands in contrast to other methods like the allowance method, which anticipates future uncollectible accounts and records an estimate prior to any specific account being deemed uncollectible. The deferred expense method and accrual method relate to other categories of expenses and revenues rather than specifically addressing how uncollectible accounts are recognized in accounting.