AWS Certified Solutions Architect Associate SAA-C03 Practice Question

CPU utilization is a useful default metric, but it is not adequate for every workload. Memory-bound applications, for example, may need policies that trigger on memory usage or other custom CloudWatch metrics you publish. AWS Auto Scaling also supports predefined metrics such as NetworkIn/NetworkOut and Application Load Balancer request count, as well as fully custom metrics, so you should choose the metric-or combination of metrics-that best reflects real resource saturation for the application. Options B is therefore correct; the other options incorrectly claim that CPU is always sufficient or that other metrics are unsupported.