#21 You build the following subquery to find the latest year in which your clinic has appointments scheduled: SELECT YEAR( MAX( last_appt.CONTACT_DATE )) FROM F_SCHED_APPT last_appt You will then compare the results of this query to YEAR( CONTACT_DATE ) in another query. Which of the following operators should you use to ensure appointments in the other query match the year from your subquery? SELECT ONE OF THE FOLLOWING (1 PT) A. = B. BETWEEN C. EXISTS D. UNION