Which of the following protocols is MOST likely to be leveraged by users who need additional information
about another user?

A.
LDAP

B.
RADIUS

C.
Kerberos

D.
TACACS+

Explanation:
A ‘directory’ contains information about users.
The Lightweight Directory Access Protocol (LDAP) is a directory service protocol that runs on a layer
above the TCP/IP stack. It provides a mechanism used to connect to, search, and modify Internet
directories.
The Lightweight Directory Access Protocol (LDAP) is an open, vendor-neutral, industry standard
application protocol for accessing and maintaining distributed directory information services over an
Internet Protocol (IP) network. Directory services play an important role in developing intranet and
Internet applications by allowing the sharing of information about users, systems, networks, services, and
applications throughout the network. As examples, directory services may provide any organized set of
records, often with a hierarchical structure, such as a corporate email directory. Similarly, a telephone
directory is a list of subscribers with an address and a phone number.
Incorrect Answers:
B: Remote Authentication Dial In User Service (RADIUS) is a networking protocol that provides centralized
Authentication, Authorization, and Accounting (AAA) management for users who connect and use a
network service. It is not used by users who need additional information about another user. Therefore,
this answer is incorrect.
C: Kerberos is an authentication protocol. It is not used by users who need additional information about
another user. Therefore, this answer is incorrect.D: Terminal Access Controller Access-Control System (TACACS +) is a client/server-oriented environment,
and operates in a manner similar to RADIUS. It is not used by users who need additional information
about another user. Therefore, this answer is incorrect.

https://msdn.microsoft.com/en-us/library/aa367008(v=vs.85).aspx
https://en.wikipedia.org/wiki/Lightweight_Directory_Access_Protocol