Which graph does deadlock detection use when every resource has a single instance?
Correct answer C. A wait-for graph obtained by removing resource nodes from the resource-allocation graph
Explanation
For single-instance resources, the detector collapses the resource-allocation graph into a wait-for graph, with an edge from Pi to Pj when Pi waits for a resource that Pj holds. The system is deadlocked exactly when this graph contains a cycle, which can be checked periodically. Multiple-instance resources need a Banker-like detection algorithm instead.
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