PCA (Prometheus Certified Associate) sample exam question with answer 523

Question:
What is the purpose of a histogram in Prometheus?

1. To represent a single numerical value that can arbitrarily go up and down
2. To sample observations and count them in configurable buckets
3. To represent a single monotonically increasing counter whose value can only increase or be reset to zero on restart
4. To calculate configurable quantiles over a sliding time window

Answer:
B - is the correct answer. Histograms are used to measure the distribution of a metric over time, such as request durations or response sizes. Histograms count observations in configurable buckets and provide a sum of all observed values. They also provide cumulative counters for each bucket, the total sum of all observed values, and the count of events that have been observed