Which of the following components are normally required to secure wireless 802.11 networks?
Each correct answer represents a complete solution. Choose all that apply.

A.
Segmentation

B.
Authentication

C.
Strong encryption

D.
Accessibility

Explanation:
The three major components that are normally required to secure wireless 802.11 networks are as follows. Strong encryption. Encryption is the process of conversion of data into a form that cannot be easily understood by unauthorized persons. The encrypted data is known as cipher text. The cipher text can be converted back into its original form by a process known as decryption. Decryption is the reverse process of encryption. As data is transmitted freely and openly in the air, proper protection is needed in order to secure data, so strong encryption is needed Authentication.
Authentication is the act of establishing or confirming something (or someone) as authentic, that is, that claims made by or about the subject are true ("authentification" is a variant of this word). This might involve confirming the identity of a person, tracing the origins of an artifact, ensuring thata product is what its packaging and labeling claims to be, or assuring that a computer program is a trusted one. Authentication is a process of verifying the user. The accuracy of the authentication can be determined by the number of factors used for the authentication, such as the following.
One-factor authentication
Two-factor authentication
Three-factor authentication
Multi-factor authentication
Segmentation. It is very important to segment users in proper groups. Once the user becomes authorized onto network resources, he can further access any of the resources. Segmentation can be achieved through a variety of means, including firewalls, routers, VPNs, and VLANs.

Answer D is incorrect. Accessibility can be viewed as the "ability to access". Once the user becomes authorized, he can access any of the resources. Without authentication, accessibility is not permitted.

Reference. http.//en.wikipediA.org/wiki/Wireless_network