What is the credit rating of the company whose average lead time is 16 days for a standard price of 18.9900 and whose last receipt date is August 27, 2011?
last receipt date is August 17, 2011 refers to LastReceiptDate> = '2011-08-17 00:00:00' and LastReceiptDate < '2011-08-18 00:00:00';
SELECT T2.CreditRating FROM ProductVendor AS T1 INNER JOIN Vendor AS T2 ON T1.BusinessEntityID = T2.BusinessEntityID WHERE T1.StandardPrice = 18.9900 AND T1.AverageLeadTime = 16 AND STRFTIME('%Y-%m-%d', T1.LastReceiptDate) = '2011-08-27'