Which option is not supported when the Cisco ASA is operating in transparent mode and also is
using multiple security contexts?

A.
NAT

B.
shared interface

C.
security context resource management

D.
Layer 7 inspections

E.
failover

Explanation:
http://www.cisco.com/en/US/docs/security/asa/asa82/configuration/guide/contexts.html
Unique Interfaces
If only one context is associated with the ingress interface, the ASA classifies the packet into that
context. In transparent firewall mode, unique interfaces for contexts are required, so this method is
used to classify packets at all times.