Explanation
A web application firewall (WAF) is a solution that inspects traffic to a cluster of web servers in a cloud environment and protects them from common web-based attacks, such as SQL injection, cross-site scripting, and denial-of-service1. A WAF can be deployed as a cloud service or as a virtual appliance in front of the web servers. A load balancer is a solution that distributes traffic among multiple web servers in a cloud environment and improves their performance, availability, and scalability2. A load balancer can also perform health checks on the web servers and route traffic only to the healthy ones. The other options are not relevant to this scenario. A CASB is a cloud access security broker, which is a solution that monitors and controls the use of cloud services by an organization's users3. A VPN is a virtual private network, which is a solution that creates a secure and encrypted connection between two networks or devices over the internet. TLS is Transport Layer Security, which is a protocol that provides encryption and authentication for data transmitted over a network. DAST is dynamic application security testing, which is a method of testing web applications for vulnerabilities by simulating attacks on them.
References: 1: https://www.imperva.com/learn/application-security/what-is-a-web-application-firewall-waf/
2: https://www.imperva.com/learn/application-security/load-balancing/
3: https://www.imperva.com/learn/application-security/cloud-access-security-broker-casb/
4: https://www.imperva.com/learn/application-security/vpn-virtual-private-network/
5: https://www.imperva.com/learn/application-security/transport-layer-security-tls/
6: https://www.imperva.com/learn/application-security/dynamic-application-security-testing-dast/
7: https://docs.microsoft.com/en-us/azure/cloud-adoption-framework/ready/azure-best-practices/plan-for-traffic-ins
8: https://docs.microsoft.com/en-us/azure/private-link/inspect-traffic-with-azure-firewall
9: https://docs.microsoft.com/en-us/azure/architecture/example-scenario/gateway/application-gateway-before-azure

The scenario describes preventive controls, which are designed to stop malicious actors from gaining access to the organization's servers. This includes using multiple access points, such as a lobby, an access control vestibule, and multiple doors leading to the server floor, as well as caging the organization's hardware. According to the CompTIA Security+ SY0-601 document, preventive controls are "designed to stop malicious actors from performing a malicious activity or gaining access to an asset." These controls can include technical solutions, such as authentication and access control systems, physical security solutions, such as locks and barriers, and administrative solutions such as policy enforcement.

Data tampering prevention can include simple security measures such as the encryption of data, and can include lengths such as using file integrity monitoring (FIM) systems for better security.
https://www.cypressdatadefense.com/blog/data-tampering-prevention/

Explanation
Credentials are sent in cleartext is the greatest risk associated with using FTP. FTP is an old protocol that does not encrypt the data or the credentials that are transmitted over the network. This means that anyone who can capture the network traffic can see the usernames and passwords of the FTP users, as well as the files they are transferring. This can lead to data breaches, identity theft, and unauthorized access. Private data can be leaked (Option A) is a possible consequence of using FTP, but not the root cause of the risk. FTP is prohibited by internal policy (Option B) is a compliance issue, but not a technical risk. Users can upload personal files (Option C) is a management issue, but not a security risk
https://www.infosectrain.com/blog/comptia-security-sy0-601-domain-5-governance-risk-and-compliance/