Jailbreaking is a process of bypassing or removing the manufacturer-imposed restrictions on a mobile device's operating system, allowing users to install unauthorized applications, modify settings, etc. It is a primary security concern for setting up a BYOD program because it can expose the device and its data to malware, vulnerabilities, unauthorized access, etc

Explanation
Implementing application execution in a sandbox for unknown software is the best defense against this scenario. A sandbox is a isolated environment that can run applications or code without affecting or being affected by other processes or systems. A sandbox can prevent malicious software from accessing or modifying sensitive data or resources, as well as limit its network communication and system privileges. A sandbox can also monitor and analyze the behavior and output of unknown software to determine if it is benign or malicious.

Single Sign-On (SSO) is a mechanism that allows users to access multiple applications with a single set of login credentials. References: CompTIA Security+ Study Guide 601, Chapter 6