A、 Add a MessageBodyMember attribute to the CodeName property and set the ProtectionLevel to Sign. Add a MessageBodyMember attribute to the SecretHandshake property and set the protectionLevel to EncryptAndSign. B、 Add a DataProtectionPermission attribute to the each property and set the ProtectData property to true. C、 Add an XmlText attribute to the CodeName property and set the DataType property to Signed. add a PasswordPropertyText attribute to the SecretHandshake property and set its value to true. D、 Add an ImmutableObject attribute to the CodeName property and set its value property to true. Add a Browsable attribute to the SecretHandshake property and set its value to false.