Explanation:

- Understanding the Role of Operating Systems:

- Operating systems (OS) create a bridge between hardware and the user, offering a user-friendly environment for interaction and application execution.

- A primary function of an OS is to provide a graphical user interface (GUI) or a command line interface for user interaction.

- Option Analysis:

- Option 1 - Enables the programmer to draw a flowchart: Incorrect, as this task is performed by specific software tools, not the OS.

- Option 2 - Provides a layered, user-friendly interface: Correct, as operating systems are designed to offer a user-friendly and accessible interface.

- Option 3 - Links a program with subroutine it references: Incorrect, as linking is typically handled by a linker, part of the development process rather than the OS.

- Option 4 - All of the above: Incorrect, as Options 1 and 3 do not correctly describe the primary roles of an OS.

- The correct answer is provides a layered, user friendly interface from Option 2.