Refer to the exhibit. Which two statements about the SDF Locations window of the IPS Rule wizard are true？（）
- AAn HTTP SDF file location can be specified by clicking the Add button.
- BIf all specified SDF locations fail to load， the signature file that is named default.sdf will be loaded.
- CThe Autosave feature automatically saves the SDF alarms if the router crashes.
- DThe Autosave feature is automatically enabled for the default built-in signature file.
- EThe name of the built-in signature file is default.sdf.
- FThe Use Built-In Signatures （as backup） check box is selected by default.