Exam AWS Certified Cloud Practitioner topic 1 question 579 discussion

D. Implement loose coupling "Loose coupling helps isolate behavior of a component from other components that depend on it, increasing resiliency and agility. Failure in one component is isolated from others." "Loose coupling allows you to add additional code or features to a component while minimizing risk to components that depend on it. Also, scalability is improved as you can scale out or even change underlying implementation of the dependency." https://docs.aws.amazon.com/wellarchitected/latest/reliability-pillar/rel_prevent_interaction_failure_loosely_coupled_system.html

D is the answer.

D. Implement loose coupling Implementing loose coupling is an architectural best practice that helps to prevent one system component from negatively impacting another component. Loose coupling is achieved by designing the system so that each component is independent of the others and only communicates with them through a well-defined interface. This allows changes to be made to one component without affecting the others, and also allows the system to be more resilient to failures. When components are loosely coupled, it's easier to scale, maintain, and update the system, as well as to troubleshoot issues. Use request throttling is a technique to control the rate of incoming requests to a service, avoiding overloading it, but it does not prevent one component from impacting another. A stateful service is one that maintains state information across requests, which could cause issues if not properly managed. Implementing automatic data backups is a security best practice, but it doesn't prevent one component from impacting another.

Answer is D