Which statement is NOT valid about creating an alarm query in Oracle Cloud Infrastructure (OCI) Monitoring?

In Oracle Cloud Infrastructure (OCI) Monitoring service, alarm queries are defined using Metric Query Language (MQL) expressions to evaluate metric data against specific alarm thresholds. A valid alarm query strictly requires specifying the metric name to monitor, the aggregation statistic (such as mean, max, or sum), and the sampling time interval (such as 1m or 5m). However, specifying a resource group is entirely optional. Resource groups are optional custom labels used to scope or group metrics within a metric namespace. Because alarm queries can evaluate metrics at the compartment or metric-namespace level without scoping to a resource group, requiring a resource group is not valid.

A: Metric Query Language requires a statistic function (e.g., mean, count, sum) to aggregate metric data over time. B: An explicit time interval (e.g., [1m], [5m]) is mandatory in MQL expressions to specify the aggregation window. C: A metric name is mandatory because the alarm query must target a specific metric emitted by OCI resources.

- Oracle Cloud Infrastructure Documentation, Monitoring: "Building Alarm Queries"

- Oracle Cloud Infrastructure Documentation, Monitoring: "Metric Query Language (MQL) Reference"