Write a postgre SQL statement to insert NULL values into region_id column for a row of countries table

INSERT INTO countries (country_id,country_name,region_id) 
VALUES('C3','UK',NULL);

Here is the command to see the list of inserting rows :

postgres=# SELECT * FROM countries;
 country_id | country_name | region_id
------------+--------------+-----------
 C1         | India        |      1002
 C2         | USA          |
 C3         | UK           |
(3 rows)