Question

The following subquery finds the maximum, minimum, and average number of items in sale orders (each item has its own unique orderNumber)
a) SELECT MAX(orderNumber), MIN(orderNumber), AVG(orderNumber) FROM orders;
b) SELECT MAX(items), MIN(items), AVG(items) FROM orderDetails;
c) SELECT MAX(items), MIN(items), AVG(items) FROM orders;
d) SELECT MAX(orderNumber), MIN(orderNumber), AVG(orderNumber) FROM orderDetails;