Solution
The correct answer is Option 3.
- Explanation: Least Recently Used is Page replacement policy in cache memory.
It works on the concept that pages that have been highly used in the past are likely to be significantly used again in the future.
It removes the page that has not been utilized in the memory for the longest time.
- The critical section is a code segment where the shared variables can be accessed.
An atomic action is required in a critical section
i.e. only one process can execute in its critical section at a time.
All the other processes have to wait to execute in their critical sections.
- Loosely coupled multiprocessor system
A multiprocessor is that contains more than two processors in a system.
A system is known as a loosely connected multiprocessor if there is a very low degree of coupling between these CPUs.
- A distributed operating system (DOS) is an essential type of operating system.
Distributed systems use many central processors to serve multiple real-time applications and users.
It connects multiple computers via a single communication channel.
O/S routines are distributed among available processors.