An organization is looking to add a layer of security by implementing a solution that protects hosts against known and unknown malicious attacks from the network layer up through the application layer. Which of the following fulfills this requirement?

A. Blacklisting

B. Encryption

C. Lockout

D. Whitelisting

Answer: D) Whitelisting

Explanation:

Whitelisting are used in many applications and it only allows the good known apps. Whitelisting are majorly used for security purpose as, it permits to maintain or control the misuse the apps by employees in an organisation.

Blacklisting maintain the list of denied access system and it prevented the accessing undesirable program. It is also used as security application but it is less effective than whitelisting.

Encryption are the process which are not used in the restricting application. And lockout are used by the users for entering the password for many time as possible.

Therefore, option (A) is correct.