Which of these recommended designs provides the highest availability？（）
- A map the Layer 2 VLAN number to the Layer 3 subnet
- B control route propagation to edge switches using distribute lists
- C use a Layer 2 distribution interconnection link with HSRP or GLBP
- D use a Layer 3 distribution interconnection link with HSRP or GLBP
- E use equal-cost Layer 3 load balancing on all links to limit the scope of queries in EIGRP