Final answer:
A semaphore is a synchronization tool, essentially an integer variable, used to solve the critical section problem in concurrent systems by controlling access to shared resources.
Step-by-step explanation:
A semaphore is a programming technique used to control access to a common resource in a concurrent system such as a multiprogramming environment. It is a synchronization tool that is used to solve the critical section problem, wherein multiple processes must access a shared resource without causing conflict.
Semaphores are generally implemented as a part of the operating system's kernel, and they are considered a high-level way of synchronization. The most basic form of semaphore is an integer variable that is accessed through two atomic operations, commonly referred to as wait and signal or P and V operations.
In this context, the correct answer to the question "Semaphore is a/an _______ to solve the critical section problem." is c) integer variable.
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