What Is the Major Difference Between the Two Possible Cisco

What is the major difference between the two possible Cisco IM and Presence high-availability modes?

A) Balanced mode provides user load balancing and user failover in the event of an outage. Active/standby mode provides an always on standby node in the event of an outage, and it also provides load balancing.
B) Balanced mode provides user load balancing and user failover only for manually generated failovers. Active/standby mode provides an unconfigured standby node in the event of an outage, but it does not provide load balancing.
C) Balanced mode provides user load balancing and user failover in the event of an outage. Active/standby mode provides an always on standby node in the event of an outage, but it does not provide load balancing.
D) Balanced mode does not provide user load balancing, but it provides in the event of an outage. Active/standby mode provides an always on standby node in the event of an outage, but it does not provide load balancing.