In Cisco ACI, to reassign a unique globally scoped pcTag to an Endpoint Group (EPG) that provides a global contract, one should configure subnets that are shared between VRFs (Virtual Routing and Forwarding instances) (Option C). This action allows subnets associated with an EPG to be shared across different VRFs while maintaining unique identifiers for application endpoint groups within the global scope of the fabric.
References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )