In this case, the bank seeks a solution that addresses scalability, manageability, application visibility, security (encryption and segmentation), and operational simplicity while aiming to reduce capital expenses. All these characteristics point directly to an SD-WAN architecture.

A non-managed (self-hosted) SD-WAN deployment:

Supports Zero Touch Provisioning (ZTP), reducing deployment time and operational burden.

Provides application-level visibility and intelligent path control.

Enables strong segmentation and end-to-end encryption via templates and policy engines.

Helps reduce CAPEX through the use of lower-cost broadband and centralized management.

While a “managed SD-WAN” solution (Option C) might be suitable in some cases, it typically involves higher OPEX. The question emphasizes CAPEX reduction, favoring an in-house SD-WAN solution.

This approach aligns with CCDE v3.1's “Scenario-based Design Strategy Guidance” and “Technology Comparisons and Use Cases” topics that emphasize selecting technologies aligned to business objectives and architectural scalability.

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