What is the name of the supplier that supplies the most products to the company?
name of the supplier refers to SupplierID; the most product refers to max(count(ProductID))
SELECT T1.SupplierID FROM Products AS T1 INNER JOIN Suppliers AS T2 ON T1.SupplierID = T2.SupplierID GROUP BY T1.SupplierID ORDER BY COUNT(*) DESC LIMIT 1