Which design consideration should be observed when EIGRP is configured on Data Center switches?

A customer's current Layer 2 infrastructure is running Spanning Tree 802.1d, and all configuration changes are manually implemented on each switch. An architect must redesign the Layer 2 domain to achieve these goals:
* reduce the impact of topology changes
* reduce the time spent on network administration
* reduce manual configuration errors
Which two solutions should the architect include in the new design? (Choose two.)

Refer to the exhibit. A network architect is preparing a network design based on the EIGRR.
Routers are connected using a cat6a cable type and the inter-router connection speed is limited to 10 Mbps due to distance. During the pilot phase, a DUAL-3-SIA error message is visible.
Which action must the engineer take to create a stable design?

Refer to the exhibit. An engineer must design a WAN solution so that ISP-1 is always preferred over ISP-2. The path via ISP-2 is considered as a backup and must be used only when the path to ISP-1 is down. Which solution must the engineer choose?

Refer to the exhibit.

An architect is designing a routing solution for a company. The new design will add a circuit routers C and D to protect against loss of connectivity to 10.0.4.0/24 during a link failure between routers B and D. Which solution must the architect choose?