Which three options are valid when Cisco Unified Customer Voice Portal comprehensive call flow and survivability service handles SIP REFER? (Choose three.)
A . SIP trunk alternate destination routing (ADR) must be disabled for REFER
B . An application-controlled alternative is to set an ECC variable (user.sip.refertransfer) to the value y in the Unified ICM script
C . Router require on a failed SIP Refer transfer where the survivability service is not handling the SIP Refer request
D . Direct Refer transfer using label works only if Send To VRU node is NOT used before the Refer
E . Unified ICM sends Unified CVP a routing label with a format of rfXXXX
F . Standalone Cisco Unified CVP with ICM Lookup label
Answer: BCE