Which security method does a Cisco guest wireless deployment that relies on Cisco ISE guest portal for user authentication use?

A.
Layer 2 and Layer 3

B.
Layer 2 only

C.
No security methods are needed to deploy CWA

D.
Layer 3 only

Explanation:
http://www.cisco.com/c/en/us/support/docs/security/identity-services-engine/115732-central-web-auth-00.html