In operating systems, which of the following is a typical reason for suspending a process rather than allowing it to continue running?

Introduction / Context:
Process suspension is an important mechanism in operating systems that allows the scheduler to manage limited resources efficiently. When a process cannot make progress, it is often better to suspend it and let other processes run. This question asks you to identify a typical reason why an operating system might suspend a process instead of keeping it in the running state.

Given Data / Assumptions:

• Multiple processes compete for CPU time, memory and input or output devices.
• A suspended process is not currently eligible to run on the CPU.
• Processes may block while waiting for external events or resources.
• No numerical analysis is required.

Concept / Approach:
A process may be suspended or blocked for several reasons, such as waiting for input or output completion, waiting for a resource to become available, or being swapped out due to memory pressure. In these situations, the process cannot make progress even if it is given CPU time. Therefore, the operating system marks it as suspended or blocked and selects another ready process to run. Once the event occurs or the resource becomes free, the process can be moved back to a ready state and later scheduled again.

Step-by-Step Solution:
Step 1: Recall that suspension is used when a process cannot continue executing productively. Step 2: Identify common blocking conditions such as waiting for disk input or output, keyboard input or a synchronisation event. Step 3: Recognise that suspending such a process allows the CPU to be used by another ready process. Step 4: Examine the options and find the one that explicitly describes a process waiting for input or output or a resource. Step 5: Confirm that the other options describe different process states, such as termination or creation, which are not typical reasons for suspension.

Verification / Alternative check:
Classic process state diagrams in operating system courses show transitions from running to blocked or suspended when a process issues an input or output request. The process returns to the ready queue only after the request completes. This model exactly matches the explanation that awaiting an event or resource motivates suspension, reinforcing that the correct option describes this scenario.

Why Other Options Are Wrong:
Option B describes a process that has terminated and entered a zombie state, which is not a suspension for later continuation of execution. Option C refers to process creation, which is handled through admission and initial scheduling, not suspension of an existing running process. Option D incorrectly suggests that efficiency is rewarded by suspension; in reality, efficient processes are more likely to be allowed to continue or to be scheduled frequently, not suspended.

Common Pitfalls:
Students sometimes confuse the blocked state with the terminated state, assuming that a process that is not running is always finished. Another pitfall is to ignore the difference between waiting for input or output and waiting for the scheduler; only the former usually causes a blocked or suspended state due to resource or event dependency.

Final Answer:
A process is typically suspended when it is waiting for an input or output event or another resource, so the operating system can free the CPU for other ready processes.