Interrupt Vector. Choose one answer. * The major difficulty in designing an operating system using the layered approach is O Appropriately defining the various layers Making sure that each layer hides certain data structures, hardware, and operations from higher level layers Debugging a particular layer Making sure each layer is easily converted to modules Choose one answer An operating system can be viewed as a resource allocator because: O it acts as the manager of system resources. O it must decide how to allocate system resources to specific programs and users. it must use system resources efficiently and fairly All of the above Choose one answer. MacBook Air Choose one answer. operating systems are designed primarily to maximize resource utilization. O Handheld computer Mainframe O Network Choose one answer. Which operating system structure(s) allow(s) direct communication among all operating system services? Layered approach Microkernel approach Modular approach O All of the above Indicate whether each statement is True or False. The functions that make up an API typically invoke actual system calls on behalf of the application programmer. True False Indicate whether each statement is True or False. Using system calls directly in your program guarantees portability of your code. True O False MacBook Air