Question: How many customers in Chicago ordered at least 10 Cardinal EasyOpen D-Ring Binders in a single order?
SQL: SELECT COUNT(DISTINCT T1.`Customer ID`) FROM west_superstore AS T1 INNER JOIN people AS T2 ON T1.`Customer ID` = T2.`Customer ID` INNER JOIN product AS T3 ON T3.`Product ID` = T1.`Product ID` WHERE T3.`Product Name` = 'Cardinal EasyOpen D-Ring Binders' AND T2.City = 'Chicago' AND T1.Quantity > 10