Use the following SELECT statement to answer.

1 SELECT customer#, COUNT(*)
2 FROM customers JOIN orders USING (customer#)
3 WHERE orderdate > '02-APR-09'
4 GROUP BY customer#
5 HAVING COUNT(*) > 2;

Because the SELECT clause contains the Customer* column, which clause must be included for the query to execute successfully?
a. 1
b. 3
c. 4
d. 5