Part B: You are in the last part of audit evidence gathering for the Bosco Corporation with a year end of March 31, 2021. Bosco's CEO, Rachel Bosco, states that any invoices relating to the March 31, 2021 year-end that were received after the year-end voucher register was closed for the March 31, 2021 year were recorded by Bosco's CFO via a year-end adjusting journal for the year under audit. Bosco's internal audit team also tested for unrecorded liabilities after the March 31 year-end close. Rachel has indicated she will also provide a letter certifying there are no unrecorded liabilities for the-March 31, 2021 year end. Required: (a) Should your procedures for unrecorded liabilities be affected by the fact that the client made a journal entry to record March 31, 2021 that were received later? Explain your reasoning for your answer. (b) Should your test for unrecorded liabilities be affected by the fact that a letter is obtained in which a responsible management official certifies, to the best of that person's knowledge, all liabilities that have been recorded? Explain your reasoning for your answer. (c) Should your test for unrecorded liabilities be eliminated or reduced because of the internal audit work? Explain your reasoning for your answer (NOTE: Consider AU-C Section 610). (d) What sources, in addition to the voucher register for the new year end, should you consider for locating possible unrecorded liabilities