The correct answer is A. User id.
Database access levels are specified so as to define who can access what in a database. It is identified through a user id. A user id is a unique identifier that is used to authenticate a user and grant them access to a database. The user id is typically a combination of letters and numbers, and it is often used in conjunction with a password to provide additional security.
Option B, password, is also a way to identify a user. However, it is not the only way. A user id can also be used to identify a user, and it is often used in conjunction with a password to provide additional security.
Option C, status, is not a way to identify a user. Status is a property of a user that indicates their level of access to a database. For example, a user with the status “admin” may have full access to a database, while a user with the status “user” may only have limited access.
Option D, none of the above, is also incorrect. A user id is a way to identify a user, and it is often used in conjunction with a password to provide additional security.