Which supplier supplies the most amount of products?
supplier refers to SupplierID; most amount refers to max(count(ProductID))
SELECT T2.CompanyName FROM Products AS T1 INNER JOIN Suppliers AS T2 ON T1.SupplierID = T2.SupplierID GROUP BY T2.SupplierID, T2.CompanyName ORDER BY COUNT(T1.ProductName) DESC LIMIT 1