Explanation
A /28 subnet is a subnet that has a network prefix of 28 bits and a host prefix of 4 bits. A /28 subnet can support up to 16 hosts (14 usable hosts) and has a subnet mask of 255.255.255.240. Using a /28 subnet can meet the minimum IP requirement for deploying a web application in a public cloud with two web servers, two database servers, and a load balancer that is accessible over a single public IP, taking into account the gateway for this subnet and the potential to add two more web servers. Using a /28 subnet can provide enough host addresses for the current and future web servers, database servers, load balancer, and gateway, as well as allow for some growth or redundancy. References: CompTIA Cloud+ Certification Exam Objectives, page 15, section 2.8

Explanation
A WAF (web application firewall) is a type of firewall that protects web applications from common web-based attacks, such as SQL injection, cross-site scripting, and denial-of-service. A WAF can be deployed on the load balancer or on the web servers to filter and block malicious requests before they reach the application or the database. A WAF is the most likely option to improve the site security in this scenario, as it can prevent attacks that target the web application layer.
References:
Web Application Firewall (WAF) - AWS WAF, AWS Firewall Manager, and AWS Shield Advanced What is a Web Application Firewall (WAF)?
Web Application Firewall (WAF) - Oracle Cloud Infrastructure

Explanation
Distributed denial-of-service (DDoS) protection is a type of security solution that detects and mitigates DDoS attacks that aim to overwhelm or disrupt a system or service by sending large volumes of traffic from multiple sources. DDoS protection can prevent such disruptive traffic from reaching the web servers by filtering out malicious or unwanted traffic and allowing only legitimate traffic to pass through. DDoS protection can also help maintain the availability and functionality of web services and applications during a DDoS attack.
References: CompTIA Cloud+ Certification Exam Objectives, page 14, section 2.7

Explanation
The best way to resolve the issue where the autoscaling configuration is creating a new VM every five minutes after deploying a new CI/CD tool to automate new releases of the web application and configuring a script to be executed by the VMs during bootstrapping is to debug the script and redeploy it. Debugging the script means finding and fixing any errors or bugs in the code or logic of the script that may cause unexpected or undesired behavior, such as triggering the autoscaling condition or failing to complete the bootstrapping process. Redeploying the script means updating or replacing the existing script with the corrected or improved version of the script. Reference: [CompTIA Cloud+ Certification Exam Objectives], Domain 4.0 Troubleshooting, Objective 4.5 Given a scenario, troubleshoot automation/orchestration issues.

Explanation
A password and a physical token are two factors of authentication that can provide a higher level of security than a password alone. A physical token is a device that generates a one-time code or password that the user must enter along with their password to access the cloud provider console. This is an example of multi-factor authentication (MFA), which requires the user to present two or more pieces of evidence to prove their identity. MFA can prevent unauthorized access even if the password is compromised, as the attacker would also need to have the physical token to log in.