Round robin is an example of load balancing. Load balancing is the method of distributing network traffic equally across a pool of resources that support an application. Load balancing improves application availability, scalability, security, and performance by preventing any single resource from being overloaded or unavailable. Round robin is a simple load balancing algorithm that assigns each incoming request to the next available resource in a circular order. For example, if there are three servers (A, B, C) in a load balancer pool, round robin will send the first request to server A, the second request to server B, the third request to server C, the fourth request to server A again, and so on.

The most likely cause of the servers displaying the wrong time is A. A firewall. A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predefined rules. A firewall can block or allow certain ports, protocols, or applications that are used for network communication.
One of the protocols that is used for time synchronization is the Network Time Protocol (NTP), which requires the use of UDP port 123 for all time synchronization1. If a firewall blocks this port, it can prevent the servers from obtaining the correct time from the time source. Therefore, the server administrator should check the firewall settings and make sure that UDP port 123 is allowed for NTP traffic.

A tabletop exercise is a type of disaster recovery testing exercise that is primarily used to discuss incident response strategies for critical systems without affecting production data. A tabletop exercise is a discussion-based session where team members meet in an informal, classroom setting to review their roles and responsibilities during an emergency and their responses to a hypothetical scenario. A facilitator guides the participants through the discussion and evaluates the strengths and weaknesses of the preparedness program. A tabletop exercise does not involve any actual deployment of resources or activation of systems12. A backup recovery test (B) is a type of disaster recovery testing exercise that involves restoring data from backup media to verify its integrity and availability. A backup recovery test may affect production data if it is not performed on a separate environment. A live failover is a type of disaster recovery testing exercise that involves switching operations from a primary site to a secondary site in case of a failure or disruption. A live failover may affect production data if it is not performed on a simulated environment. A hot-site visit audit (D) is a type of disaster recovery testing exercise that involves inspecting and evaluating a hot site, which is a backup location that has fully operational equipment and resources to resume business operations in case of a disaster. A hot-site visit audit does not involve any discussion of incident response strategies or simulation of scenarios. Reference: 1 https://www.ready.gov/testing-exercises 2 https://www.ready.gov/exercises