PCA (Prometheus Certified Associate) sample exam question with answer 97

Question:
What is a Prometheus metrics registry?

1. A set of metrics in an instrumented application that will be returned when scraped
2. A code library used for exposing Prometheus metrics
3. A documentation site detailing the metrics provided by a specific exporter or instrumentation
4. A documentation site detailing all of the public exporters and instrumentations

Answer:
A - Correct answer. A Prometheus metrics registry is a code concept within each Prometheus client library where metrics are registered to be returned when scraped. More on client libraries overall structure
B - his the definition of a Prometheus client library.
C - this documentation is not the metrics registry.
D - While the Prometheus documentation site does maintain a large list of available exporters, that is not what a metrics registry is