Final answer:
Column-Level security should be used to assign permissions for multiple columns in one GRANT or DENY statement, allowing for granular control over access to data.
Step-by-step explanation:
If you are looking to assign permissions for multiple columns in one GRANT or DENY statement, you should use Column-Level security. This approach allows you to specify permissions on individual columns within a table rather than on the entire table or on specific rows. Using this method, you can ensure that users have access only to the data they require and nothing more, enhancing data security.