In Huawei CloudFabric Solution, OSPF or BGP can be used on the underlay network of a DC.

In Huawei's CloudFabric Data Center Network Solution, the underlay network is responsible for providing IP reachability between network devices. To achieve this, the solution supports the use of standard routing protocols. Both OSPF and BGP (specifically EBGP) are valid and commonly deployed options for building the underlay routing plane. The choice between them typically depends on the scale of the data center, with OSPF being simpler for smaller deployments and BGP offering superior scalability for larger ones.

B. This option is incorrect because the statement in A is factually true according to official Huawei documentation and common industry practice for data center fabrics.

- Huawei CloudFabric Data Center Network Solution Technical Post-Sales Training V1.0. (2021). "Underlay Network Design" section describes the use of both OSPF and BGP for establishing underlay routes.

- Huawei HedEx Documentation for CloudEngine Data Center Switches. The configuration guides for CE series switches detail the procedures for configuring both OSPF and BGP in a spine-leaf topology.