Access to the superuser or root account on a server must be limited to only the system administrators that must absolutely have this level of access. Use of programs such as SUDO is recommended to give limited and controlled root access to administrators that have a need for such access.

Section: Security Assessment and Testing

A Cyber-Physical System (CPS) is a system that integrates physical processes, computational capabilities, and communication networks. A CPS can have various applications, such as smart grids, autonomous vehicles, or industrial control systems. When designing a CPS, the first consideration for a security practitioner should be the risk assessment of the system, which is the process of identifying, analyzing, and evaluating the potential threats, vulnerabilities, and impacts that could affect the system. A risk assessment can help to determine the security requirements, objectives, and controls for the CPS, as well as the priorities and resources for the security implementation and management. Resiliency, detection, and topology are all important aspects of CPS security, but they are not the first consideration, as they depend on the outcome of the risk assessment.

The network layer contains the Internet Protocol (IP), the Internet Control
Message Protocol (ICMP), and the Internet Group Management Protocol (IGMP)
The following answers are incorrect:
Datagram Layer. Is incorrect as a distractor as there is no Datagram Layer.
Transport Layer. Is incorrect because it is used to data between applications and uses the
TCP and UDP protocols.
Data Link Layer. Is incorrect because this layer deals with addressing hardware.