The correct option is They can be scaled horizontally and recover with less complexity.

Designing services to avoid local state makes individual instances interchangeable which lets orchestration and autoscaling add or remove replicas without complex data synchronization. This is why They can be scaled horizontally and recover with less complexity is the best answer.

Cloud Run is incorrect because it names a platform rather than explaining a design benefit. The question asks why engineers prefer a stateless design and not which service can run that design.

They reduce the reliance on persistent storage is misleading because stateless services typically move state to external durable stores rather than removing the need for persistence. The design shifts where data is stored and does not inherently eliminate persistent storage.

Troubleshooting services is simpler without local state is not the primary reason and can be false in practice. Removing local state can improve reproducibility but debugging can still be complex and local state can sometimes aid diagnosis.

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