Implementing Cisco IP Switched Networks (SWITCH v2-0) (#510)

Assuming that preempt is not configured, when does a router in an HSRP group assume the role of the active router for the group?

A router in standby status will become the active router if it has a higher priority than the active router.
A router in standby status will become the active router when it does not detect three consecutive hello messages from the active router.
A router in standby status will become the active router when it does not detect any hello messages from the active router within the configured holdtime.
A router in listening status will become the active router when it does not detect any hello messages from the active router within the configured holdtime.