Which two statements would execute successfully?

Examine the structure of the MARKS table:
Exhibit:

Which two statements would execute successfully? (Choose two.)

A.
SELECT student_name,subject1
FROM marks
WHERE subject1 > AVG(subject1);

B.
SELECT student_name,SUM(subject1)
FROM marks
WHERE student_name LIKE ‘R%’;

C.
SELECT SUM(subject1+subject2+subject3)
FROM marks
WHERE student_name IS NULL;

D.
SELECT SUM(DISTINCT NVL(subject1,0)), MAX(subject1)
FROM marks
WHERE subject1 > subject2;