Which site-to-site VPN solution allows Cisco routers， PIX Firewalls， and Cisco hardware clients to act as remote VPN clients in order to receive predefined security policies and configuration parameters from the VPN headend at the central site？（）

A.to ensure a loop-free topology
B.to protect against user-side loops
C.in order to support business applications
D.because of the risk of lost connectivity without STP
E.for the most deterministic and highly available network topology

A.19 dBm
B.7 dBm
C.10 dBm
D.6 dBm
E.5 dbm to 10 dBm

A.another name for a firewall deployed in routed mode
B.another name for a firewall deployed in transparent mode
C.a separation of multiple firewall security contexts on a single firewall
D.a firewall that， when deployed in routed mode， can support up to 1000 VLANs per context
E.a firewall that has multiple contexts， all of which share the same policies （such as NAT and ACLs）