Which two SQL statements would execute successfully?

Examine the structure of the PROGRAMS table:
name Null Type
PROG_ID NOT NULL NUMBER(3)
PROG_COST NUMBER(8,2)
START_DATE NOT NULL DATE
END_DATE DATE
Which two SQL statements would execute successfully? (Choose two.)

A.
SELECT NVL(ADD_MONTHS(END_DATE,1),SYSDATE)
FROM programs;

B.
SELECT TO_DATE(NVL(SYSDATE-END_DATE,SYSDATE))
FROM programs;

C.
SELECT NVL(MONTHS_BETWEEN(start_date,end_date),’Ongoing’)
FROM programs;

D.
SELECT NVL(TO_CHAR(MONTHS_BETWEEN(start_date,end_date)),’Ongoing’) FROM programs;