Implementing Cisco IP Switched Networks (SWITCH v2-0) (#28)

Which of the following is required to allow load balancing between three HSRP routers connected to the same LAN?

A single HSRP group with all three routers as active routers for the group
A single HSRP group with one active router for the group
Two HSRP groups, each with an active router
Two HSRP groups with one active router for both the groups
Three HSRP groups, each with an active router
Three HSRP groups with one active router for all groups