The correct answer is B, 'Ability to upgrade components independently'. Decoupling in AWS Cloud architecture refers to the practice of separating components so that they can operate independently. This allows for individual components to be updated, maintained, or replaced without affecting the entire system. It provides flexibility and agility in managing and evolving the architecture over time. Options A, C, and D do not directly relate to the concept of decoupling, as decoupling does not inherently reduce latency, decrease costs, or reduce the number of components to manage.