SQL & PL/SQL :: Join Query - Retrieve Last Or First Rank Row?

the following statement gives each customer owns how many promotions.

Q:) how do i retrieve a customer who has max. promotions?

SELECT C.CUSTOMER_ID,COUNT(P.PROMOTION_ID)
FROM PROMOTIONS P,CUSTOMERS C
WHERE C.CUSTOMER_ID = P.CUSTOMER_ID
GROUP BY C.CUSTOMER_ID
=====================================================
CUSTOMER_ID COUNT(P.PROMOTION_ID)
-------------------------------------
001 | 5
002 | 8
003 | 4
004 | 6
005 | 5
006 | 3