Given below is a list of functions and their purpose in random order.
Function Purpose
1)NVL a) Used for evaluating NOT NULL and NULL values
2)NULLIF b) Used to return the first non- null values in a list of expressions
3)COALESCE c) Used to compare two expressions. If both are same, it returns NULL;
otherwise, it returns only the first expression.
4)NVL2 d) Used to convert NULL values to actual values
Identify the correct combination of functions and their usage.
A.
1-a,2-c,3-b,4-d
B.
1-d,2-c,3-b,4-a
C.
1-b,2-c,3-d,4-a
D.
1-d,2-b,3-c,4-a