The correct answer is B: Use Istio's fault injection on the particular microservice whose faulty behavior you want to simulate. Istio is a service mesh that provides advanced traffic management, including fault injection capabilities. This allows you to deliberately introduce errors such as delays or crashes into a specific microservice, effectively simulating its failure without affecting other parts of your application. This targeted approach ensures that you can observe the application's behavior and resilience in the face of specific microservice failures.