To implement a standard Adminhtml form for a custom data model, which two of the following must you do?
(Choose two)

A.
Declare your module’s block class prefix in the config.xml file.

B.
Implement a sub-class of Mage_Adminhtml_Block_widget_Form.

C.
Implement a sub-class of Mage_Adminhtml_Block_Form_Abstcact.

D.
Create sub-classes of Mage_Adminhtml_Block_Form_Element_Abstract for each form field to be
presented.

E.
Add a set of configuration values in the module’s config.xml defining the form fields to be displayed,