在 Oracle 数据库中，有一张订单表（ORDERS），包含订单编号（ORDER_ID）、客户编号（CUSTOMER_ID）、订单日期（ORDER_DATE）、订单金额（AMOUNT）字段，还有一张客户表（CUSTOMERS），包含客户编号（CUSTOMER_ID）、客户姓名（CUSTOMER_NAME）、客户地址（CUSTOMER_ADDRESS）字段。现要查询出每个客户的订单总金额，并按照订单总金额降序排列，以下哪个 SQL 语句是正确的？ABD A SELECT CUSTOMERS.CUSTOMER_ID, SUM(ORDERS.AMOUNT) AS TOTAL_AMOUNT FROM CUSTOMERS JOIN ORDERS ON CUSTOMERS.CUSTOMER_ID = ORDERS.CUSTOMER_ID GROUP BY CUSTOMERS.CUSTOMER_ID ORDER BY TOTAL_AMOUNT DESC; B SELECT CUSTOMERS.CUSTOMER_ID, SUM(ORDERS.AMOUNT) AS TOTAL_AMOUNT FROM CUSTOMERS, ORDERS WHERE CUSTOMERS.CUSTOMER_ID = ORDERS.CUSTOMER_ID GROUP BY CUSTOMERS.CUSTOMER_ID ORDER BY TOTAL_AMOUNT DESC; C SELECT CUSTOMER_ID, SUM(AMOUNT) AS TOTAL_AMOUNT FROM ORDERS GROUP BY CUSTOMER_ID ORDER BY TOTAL_AMOUNT DESC; D SELECT CUSTOMERS.CUSTOMER_ID, SUM(ORDERS.AMOUNT) AS TOTAL_AMOUNT FROM CUSTOMERS INNER JOIN ORDERS ON CUSTOMERS.CUSTOMER_ID = ORDERS.CUSTOMER_ID GROUP BY CUSTOMERS.CUSTOMER_ID ORDER BY TOTAL_AMOUNT DESC;