You are the auditor of a client where you believe there is significant risk that the purchases account at year-end contains items that should have been debited to other expense accounts. Clearly answer each of the following: A.) In order to detect this type of error in the purchases account, which audit procedure would be most appropriate, vouching or tracing? B.) Which management assertion for the purchases account is questionable, occurrence or completeness? Explain your answers and be specific.