In a High Availability (HA) Environment, What Is the PRIMARY

In a High Availability (HA) environment, what is the PRIMARY goal of working with a virtual router address as the gateway to a network?

A) The second of two routers can periodically check in to make sure that the first router is operational.
B) The second of two routers can better absorb a Denial of Service (DoS) attack knowing the first router is present.
C) The first of two routers fails and is reinstalled, while the second handles the traffic flawlessly.
D) The first of two routers can better handle specific traffic, while the second handles the rest of the traffic seamlessly.