A4.14 A system with two dual-core processors has four processors available for scheduling. A CPU- intensive application is running on this system. All input is performed at program start-up, when a single file must be opened. Similarly, all output is performed just before the program terminates, when the program results must be written to a single file. Between startup and termination, the program is entirely CPU-bound. Your task is to improve the performance of this application by multithreading it. The application runs on a system that uses the one-to-one threading model (each user thread maps to a kernel thread). How many threads will you create to perform the input and output? Explain. How many threads will you create for the CPU-intensive portion of the application? Explain.