Jenna is working on the audit of a client's accounts receivable. During the last few weeks, she has conducted interviews with the accounts receivable manager, the chief financial officer, and staff working in the accounts receivable department. She has overseen the external confirmations of accounts receivable, 30% of which required the recipient to respond whether or not the amount stated was correct. Jenna also inspected subsequent cash receipts from the client's customers. She vouched a sample of accounts receivable balances back to the underlying invoices, cash receipts and sales returns, and traced a sample of these documents to the accounts receivable ledger.

a. List the audit procedures used by Jenna to gather evidence and comment on the reliability of the evidence.

b. Relate each type of evidence to the relevant accounts receivable assertions.