What action would you take to ensure that a user cannot connect to the database instance by merely logging in to a remote machine?

A user, who is authenticated externally, logs in to a remote machine and connects to the database instance.
What action would you take to ensure that a user cannot connect to the database instance by merely logging in to a remote machine?

A.
Set the REMOTE_LOGIN_PASSWORD_FILE parameter to NONE

B.
Set OS_ROLES parameter to FALSE

C.
Set REMOTE_OS_ROLES to FALSE

D.
Set the REMOTE_OS_AUTHENT parameter to FALSE