Answer:
B
Explanation:
An authentication server server tracks who is logging on to the network as well as which services on the network are available to each user. It also does the job of providing a network service that applications can use to authenticate the credentials, that are oftentimes account names and passwords, of their users. Authentication server is also used as the basis for authorization.
The answer here is Blind carbon copy (bcc).
The original recipients of the letter are unable to see (blind) who else receives a copy if those parties are on the bcc list.
