An operating system is a program that acts as a user-computer GUI (Graphical user interface). It controls the execution of all types of applications. Important Points The operating system performs the following functions in a device. Communication management:It acts as an interface between computer hardware components and the user. Memory management: The memory management module performs the task of allocation and de-allocation of memory space to programs in need of these resources. ?The need for memory management in OS is to allocate and de-allocate memory space to process in demand of resources or if they are running out of memory that leads to alerts called file system and disk space is high or full. The operating system can do resource allocation and prevent the system from overloading. Peripheral devices management:The OS uses programs called device drivers to manage connections with peripherals. It handles the translation of requests between a device and the computer. defines where a process must put outgoing data before it can be sent, and where incoming messages will be stored when they are received. I/O System Management: One of the main objects of any OS is to hide the peculiarities of that hardware device from the user. Security:Security module protects the data and information of a computer system against malware threats and authorized access. Command interpretation: This module is interpreting commands given by the acting system resources to process those commands. Additional InformationAn operating system does not provide internet access. Note that it should not be confused with a web operating systemA Web Operating System is an internet-based user interface that allows people to access applications not stored on their computers but completely or partly on the InternetIt is a dummy operating system that does not directly interact with computer hardware and depends on the traditional operating system to workThus we conclude that the correct answer is A, B, and C only