Best practice and accounting standards require that receivables unlikely to be collected be written off to avoid overstating assets. Internal audit should recommend that management review the receivables and write off uncollectible debts accordingly.

Option A (escalation to the board) is premature; it should first be addressed with management. Option B (removing from cash flow statement) is not correct because write-offs affect the balance sheet and income statement, not just cash flows. Option D ignores a material risk of misstated financial statements.