PCA (Prometheus Certified Associate) sample exam question with answer 102

Question:
You are instrumenting an application called agate for Prometheus. This application has a subsystem called remed that handles automated script-based remediations. You want to define a metric that gives the number of remediation processes currently running.
Which of the following is the most appropriate “fully-qualified” metric name?

1. agate_remed_processes_running
2. agate-remed-processes-running
3. processes_running
4. remed_processes_running

Answer:
A - is the correct answer. Check metric names
B - metric names cannot contain hyphens
C - it is not fully-qualified with the name of the application and the subsystem
D - it is not fully-qualified with the name of the application