The following query returns the customer who has the highest payment. (Assume all data are in the same table)
a) SELECT customer_id, MAX(payment) FROM customers;
b) SELECT customer_id, payment FROM customers WHERE payment = MAX(payment);
c) SELECT customer_id, payment FROM customers ORDER BY payment DESC LIMIT 1;
d) SELECT customer_id, SUM(payment) FROM customers GROUP BY customer_id ORDER BY SUM(payment) DESC LIMIT 1
