Mobile Device Management (MDM) platforms enforce security policies on mobile devices, including preventing or detecting jailbreaking, which is the act of removing manufacturer restrictions on devices. Jailbroken devices bypass security protections, allow installation of unauthorized apps, expose system files, and greatly increase risk.
Security+ SY0-701 identifies MDM as a key defense for mobile ecosystems, providing controls such as:
Jailbreak/root detection
Remote wipe
App allow/deny lists
Configuration enforcement
Encryption enforcement
TPM (A) is hardware-based protection unrelated to MDM. Buffer overflow (B) and SQL injection (D) are software coding vulnerabilities not affected by mobile device policy enforcement.
Thus, the correct answer is C: Jailbreaking.

The first step in securing a newly deployed server is toclose unnecessary service ports. Open ports can expose the server to unauthorized access and potential cyber threats. By closing unused ports, the attack surface is reduced, limiting the number of entry points available to attackers.
Updating the software version (B)andupgrading the OS version (D)are important security measures but should follow the step of securing open ports to prevent immediate exposure to threats.
Adding the device to the Access Control List (ACL) (C)is a step in network security but does not directly secure the server itself against potential attacks.
Closing unnecessary ports helps in minimizing the risk of network-based attacks, such asport scanning and exploitation of default services.

Detective controls are security measures that are designed to identify and monitor any malicious activity or anomalies on a system or network. They can help to discover the source, scope, and impact of an attack, and provide evidence for further analysis or investigation. Detective controls include log files, security audits, intrusion detection systems, network monitoring tools, and antivirus software. In this case, the administrator used log files as a detective control to review the ransomware attack on the company's system. Log files are records of events and activities that occur on a system or network, such as user actions, system errors, network traffic, and security alerts. They can provide valuable information for troubleshooting, auditing, and forensics.
Reference:
Security+ (Plus) Certification | CompTIA IT Certifications, under "About the exam", bullet point 3: "Operate with an awareness of applicable regulations and policies, including principles of governance, risk, and compliance." CompTIA Security+ Certification Kit: Exam SY0-701, 7th Edition, Chapter 1, page 14: "Detective controls are designed to identify and monitor any malicious activity or anomalies on a system or network." Control Types - CompTIA Security+ SY0-401: 2.1 - Professor Messer IT ..., under "Detective Controls": "Detective controls are security measures that are designed to identify and monitor any malicious activity or anomalies on a system or network."

Full Disk Encryption (FDE) ensures that all data on the drive is encrypted, preventing unauthorized access even if the device is lost.