What is the purpose of the following query?

SELECT firstname, lastname

FROM customers NATURAL JOIN orders

WHERE shipdate $=$

$($SELECT MAX$($shipdate$)$

FROM orders

WHERE shipdate IS NULL$)$;

A The query will not return any results.

To find the names of customers whose orders have not shipped.

To find the customer with the most recent order that has not shipped.

To find the customers with the oldest order that has not shipped.