Examine the description of the CUSTOMERS table: (Exhibit) For customers whose income level has a value,

Examine the description of the CUSTOMERS table:

For customers whose income level has a value, you want to display the first name and due amount as 5% of their credit limit. Customers whose due amount is null should not be displayed.
Which query should be used?

A. SELECT cust_first_name, cust_credit_limit * .05 AS DUE_AMOUNT
FROM customers
WHERE cust_income_level <> NULL
AND due_amount <> NULL;

B. SELECT cust_first_name, cust_credit_limit * .05 AS DUE_AMOUNT
FROM customers
WHERE cust_income_level != NULL
AND cust_credit_level !=NULL;

C. SELECT cust_first_name, cust_credit_limit * .05 AS DUE_AMOUNT
FROM customers
WHERE cust_income_level != NULL
AND due_amount != NULL;

D. SELECT cust_first_name, cust_credit_limit * .05 AS DUE_AMOUNT
FROM customers
WHERE cust_income_level IS NOT NULL
AND due_amount IS NOT NULL;

E. SELECT cust_first_name, cust_credit_limit * .05 AS DUE_AMOUNT
FROM customers
WHERE cust_income_level IS NOT NULL
AND cust_credit_limit IS NOT NULL;

Correct Answer: E