Which three deployment scenarios does Cisco Configuration Assistant support？ （）

• A、 Cisco SR 500 in secure router mode， acting as a front end for Cisco Unified Communications 500
• B、 centralized Cisco Unified Communications Manager BE with Cisco Unified Communications 500 in SRST mode
• C、 Cisco SR 500 teleworker with Cisco Unified Communications 500 as VPN server
• D、 multi-site VPN with Cisco Unified Communications 500 platforms
• E、 redundant Cisco Unified Communications 500 with primary-to-backup failover
• F、 Cisco Unified Communications 500 to Cisco Unified Communications Manager SIP trunk