Which statement is true regarding the above query if on…

Evaluate the following SQL statement:
SQL> SELECT cust_id. cust_last_name FROM customers
WHERE cust_credit_limit IN
(select cust_credit_limit
FROM customers
WHERE cust_city=’Singapore’):
Which statement is true regarding the above query if one of the values generated by the sub
query is NULL?

A.
It produces an error.

B.
It executes but returns no rows.

C.
It generates output for NULL as well as the other values produced by the sub query.

D.
It ignores the NULL value and generates output for the other values produced by the sub query.