Final answer:
The control plane is responsible for network decision-making in both controller-based and regular networks, as it handles the routing and directing of data flows.
Step-by-step explanation:
The plane responsible for network decision-making in both a controller-based network and a traditional, or regular network, is the control plane. The control plane is where routing protocols operate, thereby making decisions about the best paths for data to take through the network. While the data plane handles the actual transfer of data based on the decisions made, and the management plane is used for system management tasks, it is the control plane which plays the critical role in determining how data flows should be handled and where they should be directed.