To implement route backup by configuring static floating routes, the correct approach is:

**B. The administrator needs to configure different metric values for the main static route and the standby static route**

Here's why:

- **Floating Static Routes**: This method involves configuring two static routes to the same destination, where one route is the primary (or main) route and the other is a backup (or floating) route. The primary route is chosen based on its lower metric value, while the backup route has a higher metric value, making it less preferred. The backup route will only be used if the primary route fails.

- **Metric Value**: By configuring a different metric (also called an administrative distance in some contexts) for the primary and backup routes, you ensure that the backup route only takes over if the primary route becomes unavailable.

**Other options explained:**

- **A. The administrator needs to configure different protocol priority values**: This is not applicable to static routes. Protocol priority values are used in dynamic routing protocols, not for static routes.

- **C. The administrator needs to configure different TAGs**: TAGs are not used for route prioritization in static routing. They are used in certain routing scenarios for other purposes.

- **D. The administrator only needs to configure two static routes**: Simply configuring two static routes is not enough. You must set different metric values to create a floating/static backup route mechanism.

Therefore, configuring different metric values is the correct method for implementing static floating routes....