The correct approach involves ensuring that the service can handle the predicted growth and maintain resilience against zone failure without incurring unnecessary costs. Option A is correct because it suggests verifying the maximum node pool size, enabling a horizontal pod autoscaler, and performing a load test. This approach ensures that the cluster can scale both pods and nodes as needed, based on actual load, which is efficient and cost-effective. Option B is incorrect because while the cluster autoscaler does help in scaling nodes, it's not sufficient on its own to ensure that the pods are optimally distributed and scaled based on demand. Option C is incorrect because 30% utilization does not account for the expected growth or the need for resilience against zone failure. Option D is incorrect because proactively adding a fixed 60% more capacity does not account for the dynamic nature of cloud resources and could lead to unnecessary costs. Therefore, the correct answer is A.