Which two statements best describe the wireless security standard that is defined by WPA (Choose two.)（）。

• A、It specifies use of a static encryption key that must be changed frequently to enhance security
• B、It requires use of an open authentication method
• C、It specifies the use of dynamic encryption keys that change each time a client establishes a connection
• D、It requires that all access points and wireless devices use the same encryption key
• E、It includes authentication by PSK