The virtual server's time is incorrect despite proper configuration of internal time servers.
Resolution: The engineer should manually correct the time (Option D):
If the internal time servers are configured correctly, manual adjustment is necessary.
Checking firewall rules would help identify NTP (Network Time Protocol) issues.
Replacing the CMOS battery is unlikely to be the cause of incorrect time.

A cold site is a backup facility with little or no hardware equipment installed. A cold site is the most cost-effective option among the three disaster recovery sites. However, due to the fact that a cold site doesn't have any pre-installed equipment, it takes a lot of time to properly set it up so as to fully resume business operations1.
Reference = 1: Disaster Recovery Sites Comparison: Which one to Choose? - NAKIVO(https://www.nakivo.com/blog/overview-disaster-recovery-sites/)

Round robin is a load balancing technique that distributes requests among multiple web nodes in a circular order. It ensures that each web node receives an equal amount of requests and improves the availability and performance of the web application. Verified Reference: [Round robin], [Load balancing]

The administrator should close ports 21 and 23 to secure the server properly. Port 21 is used for FTP (File Transfer Protocol), which is an unsecure protocol that allows file transfer between a client and a server over a network connection. FTP does not encrypt the data or the credentials that are transmitted, making them vulnerable to interception or modification by attackers. Port 23 is used for Telnet, which is an unsecure protocol that allows remote login and command execution over a network connection using a CLI. Telnet does not encrypt the data or the credentials that are transmitted, making them vulnerable to interception or modification by attackers.
Reference:
https://www.csoonline.com/article/3191531/securing-risky-network-ports.html