# Explanation:
* A: Virtual networks (e.g., VPNs, tunnels) create secure, logical overlays across segmented physical infrastructure such as the public Internet, effectively re-integrating remote sites into the corporate network. This re-establishes end-to-end connectivity and consistent routing/security policies.
Other options:
* B: QoS does not address segmentation or connectivity.
* C: Lax control-plane policies do not restore logical network integration and may increase security risk.
* D: Blocking traffic further limits connectivity and exacerbates segmentation.

# Explanation:
* C: In SDN, switches retain the data plane functionality-they forward packets based on flow rules received from the controller.
* A: Control plane functions are moved to the centralized controller in SDN.
* B: Southbound interfaces are present on both controllers and switches for communication.
* D: Northbound interfaces exist on controllers to interact with applications-not switches.

* B (Minimize operational costs): A common business goal to reduce long-term operating expenses.
* E (Reduce complexity): Simplifying designs reduces operational overhead, risk, and failure domains.
Why other options are incorrect:
* A: Resiliency is a design goal, but not a business objective itself.
* C: Endpoint posture is a technical security feature.
* D: Faster obsolescence contradicts business optimization.