Which of the following refers to an operating system that provides sufficient support for multilevel security and evidence of correctness to meet a particular set of government requirements?

A.
Trusted OS

B.
Distributed operating system

C.
Network operating system

D.
Real time operating system

Explanation:
Trusted Operating System (TOS) refers to an operating system that provides sufficient support for multilevel security and evidence of correctness to meet a particular set of government requirements.

The Common Criteria, combined with the Security Functional Requirements (SFRs) for Labeled Security Protection Profile (LSPP) and Mandatory Access Control(MAC) is the most common set of criteria for trusted operating system design. The Common Criteria is the outcome of a multi-year effort by the governments of the U.S., Canada. United Kingdom, France, Germany- the Netherlands and other countries with an aim to develop a harmonized security criteria for IT products.

Answer option D is incorrect. A real-time operating system (RTOS) is an operating system used to serve real-time application requests. It is an operating system that guarantees a certain capability within a specified time constraint. A key characteristic of an RTOS is the level of its consistency concerning the amount of time it takes to accept and complete an application s task. A real-time OS has an advanced algorithm for scheduling and is more frequently dedicated to a narrow set of applications.

Answer option C is incorrect. The network operating system (NOS) manages resources on a network, offers services to one or more clients, and enables clients to access remote drives as if the drives where on clients own computer. The functions provided by a network operating system are as follows:
File and print sharing
Account administration for users
Security

Answer option B is incorrect. A distributed operating system is the logical aggregation of operating system software over a collection of independent, networked, communicating, and spatially disseminated computational nodes.