Which two considerations must a network engineer have when planning for voice over wireless roaming? (Choose two.)

Which two considerations must a network engineer have when planning for voice over wireless roaming? (Choose two.)
A . Full reauthentication introduces gaps in a voice conversation.
B . Roaming time increases when using 802.1x + Cisco Centralized Key Manegement.
C . Roaming occurs when the phone has seen at least four APs.
D . Roaming occurs when the phone has reached -80 dBs or below.
E . Roaming with only 802.1x authentication requires full reauthentication.

Answer: AE