The correct answer is B: Rolling with additional batch. This deployment method allows you to update your application in batches, which helps maintain full capacity and avoid service interruption. It also uses fewer additional resources compared to the blue/green deployment, minimizing the cost. Blue/green would require double capacity for a period of time, making it more expensive. Immutable deployment introduces new instances and checks their health before swapping, which can also incur higher costs temporarily compared to the rolling with additional batch method.