Why would VRRP be implemented when configuring a new subnet in a multivendor environment?

A. when a gateway protocol is required that supports more than two Cisco devices for redundancy
B. to interoperate normally with all vendors and provide additional security features for Cisco devices
C. to ensure that the spanning-tree forwarding path to the gateway is loop-free
D. to enable normal operations to continue after a member failure without requiring a change in a host ARP cache