Which statement about the communication between interfaces on the same security level is true?

A.
Interfaces on the same security level require additional configuration to permit inter-interface
communication.

B.
Configuring interfaces on the same security level can cause asymmetric routing.

C.
All traffic is allowed by default between interfaces on the same security level.

D.
You can configure only one interface on an individual security level.

Explanation:
BD
By default, if two interfaces are both at the exact same security level, traffic is not allowed between those two
interfaces.
To permit communication between interfaces with equal security levels, or to allow traffic to enter and exit the
same interface, use the same-security-traffic command in global configuration mode.
#same-security-traffic permit {inter-interface | intra-interface}
Source: Cisco Official Certification Guide, The Default Flow of Traffic, p.422
http://www.cisco.com/c/en/us/td/docs/security/asa/asa82/command/reference/cmd_ref/s1.html