Which one of the following accurately describes the purpose of the resource helper classes instantiated through
Mage::getResourceHelper?

A.
Format values returned by the database for display in templates.
B.
Provide a convenient way to modify database table properties.
C.
Provide public access to concrete implementations of varien_Db_Adapter_Interface.
D.
Provide clean access to another module’s database tables.
E.
Wrap vendor-specific SQL additions into an RDBMS-agnostic interface.