To test the new web application in the public cloud, the systems administrator should create a replica database, synchronize the data, and switch to the new instance, and create a SSH tunnel. Creating a replica database can help minimize the downtime and ensure data consistency during the migration. Synchronizing the data can help keep the replica database up to date with the original database. Switching to the new instance can help activate the new web application in the public cloud. Creating a SSH tunnel can help bypass the network firewall and access the web application using TCP port 22. SSH is a secure protocol that can create encrypted tunnels between the local and remote hosts. By creating a SSH tunnel, the systems administrator can forward the web application traffic through the tunnel and test it using a web browser. Reference: [CompTIA Cloud+ CV0-003 Certification Study Guide], Chapter 7, Objective 7.1: Given a scenario, migrate applications and data to the cloud.

The correct answer is B. Remove rules 1, 3, and 4.
The objective is to ensure the web servers in the public subnet allow only secure communications. This means that only HTTPS traffic should be allowed on port 443, which is the standard port for secure web connections. HTTPS traffic uses the TCP protocol and encrypts the data between the client and the server.
Rule 1 allows all TCP traffic on any port from any source. This is too permissive and exposes the web servers to potential attacks or unauthorized access. Rule 1 should be removed to restrict the TCP traffic to only port 443.
Rule 3 allows all UDP traffic on any port from any source. UDP is a connectionless protocol that does not guarantee reliable or secure delivery of data. UDP is typically used for streaming media, voice over IP (VoIP), or online gaming, but not for web servers. Rule 3 should be removed to prevent unnecessary or malicious UDP traffic.
Rule 4 allows all ICMP traffic from any source. ICMP is a protocol that is used for diagnostic or control purposes, such as ping or traceroute. ICMP traffic can be used by attackers to scan or probe the network for vulnerabilities or information. Rule 4 should be removed to block ICMP traffic and reduce the attack surface.
Rule 2 allows TCP traffic on port 443 from any source. This is the desired rule that allows secure web communications using HTTPS. Rule 2 should be kept.
Rule 5 denies all other traffic that does not match any of the previous rules. This is the default rule that provides a catch-all protection for the web servers. Rule 5 should be kept.
Therefore, the analyst should remove rules 1, 3, and 4 to accomplish the objective.