Answer:
The correct option is option 4 from the options indicated below:
Step-by-step explanation:
The options are as given below
1-SELECT customer# FROM customers
UNION
SELECT customer# FROM orders;
2-SELECT customer# FROM orders
MINUS
SELECT customer# FROM customers;
3-SELECT customer# FROM orders
INTERSECT
SELECT customer# FROM customers;
4-SELECT customer# FROM customers
MINUS
SELECT customer# FROM orders;
Option 1 is not correct as it will provide the list of all the customers whether they have placed order or not.
Option 2 is not correct as it will provide the list of customers who have placed order but are not in the customers table. This will return the empty records.
Option 3 is not correct as it will provide the list of customers who have placed the order.
Option 4 is correct as it will provide the list of customers from the CUSTOMERS table which are not in the Orders table. thus the list of customers who have not placed the order yet.