The main objectives of the operating system can be summarized as follows:

• Enables the users to use computer in a convenient and efficient manner

• Hides complexity of the hardware resources from the users

• Acts as an intermediary between the computer hardware and its users.

• Manages the resources of a computer system

• To keep track of who is using which resource, granting resource requests, according for resource using and mediating conflicting requests from different programs and users

• Provides efficient and fair sharing of resources among users and programs.

The correct answer is E.