WPA2 is the only protocol among the options that supports fast roaming between networks. Fast roaming, also known as IEEE 802.11r or Fast BSS Transition (FT), enables a client device to roam quickly in environments implementing WPA2 Enterprise security, by ensuring that the client device does not need to re-authenticate to the RADIUS server every time it roams from one access point to another1. WEP, WPA, LEAP, and PEAP do not support fast roaming and require the client device to perform the full authentication process every time it roams, which can cause delays and interruptions in the network service.
References:
The Official CompTIA A+ Core 2 Study Guide2, page 263.
WiFi Fast Roaming, Simplified3