Grinner and Greeter, CPAs, were engaged to perform an audit of the financial statements of Happy, Inc. The management of Happy would not allow Grinner and Greeter to confirm any of the accounts receivable. All other audit procedures were performed as considered necessary by Grinner and Greeter and no other problems were discovered. However, Grinner and Greeter were unable to satisfy themselves as to the balance in accounts receivable. What type of audit report should be prepared