An engineer is configuring an ACI L3Out to connect the fabric to an external OSPF router. Internal EPGs must be able to reach any destination learned via the L3Out, and a contract has already been created between the internal EPG and the external EPG. When configuring the external EPG (L3 External Network), which subnet scope setting must be applied to the 0.0.0.0/0 subnet so that the external routes are properly classified into the external EPG for contract enforcement?