To which switch or switches should you provide redundant links in order to achieve high availability with reliable fast convergence in the enterprise campus?

A.
to a core switch running Cisco NSF and SSO from redundant distribution switches connected with a Layer 2 link

B.
to a core switch running Cisco NSF and SSO from redundant distribution switches connected with a Layer 3 link

C.
to two core switches from redundant distribution switches connected with a Layer 2 link

D.
to two core switches from redundant distribution switches connected with a Layer 3 link

E.
to two core switches running Cisco NSF and SSO from two redundant distribution switches running Cisco NSF and SSO