从产品表Products中查询前10行商品的单价UnitPrice之和,正确的SQL是()
A、SELECT TOP 10 SUM(UnitPrice) AS单价之和FROM Products
B、SELECT SUM(UnitPrice) AS单价之和TOP 10 FROM Products
C、SELECT TOP 10 COUNT(UnitPrice) AS单价之和FROM Products
D、SELECT SUM(UnitPrice) TOP 10 AS单价之和FROM Products