How does the custom metrics limit change if no data is written to them for one day?

The correct choice highlights that when custom metrics are not written to for one day, that inactivity does not count against your consumption limits. In Dynatrace, a custom metric that hasn’t received any data updates is effectively ignored in the metric consumption calculations. This means that if a metric is dormant due to lack of data, it won't contribute to the maximum limit of custom metrics that can be created or maintained in your environment. This allows users to optimize their custom metrics setup without being penalized for metrics that are currently inactive. Thus, you have the flexibility to manage and reduce consumption without the concern of metrics that are not actively receiving data.