In which of the following situations would one have to use an outer join in order to obtain the desired results?

A) A report is desired that lists all customers who placed an order.
B) A report is desired that lists all customers and the total of their orders.
C) A report is desired that lists all customers and the total of their orders during the most recent month, and includes customers who did not place an order during the month (their total will be zero).
D) There is never a situation that requires only an outer join.

C