PCA (Prometheus Certified Associate) sample exam question with answer 610

Question:
Which of the following PromQL expressions can be used to calculate the rate of increase of a gauge over a specified time range?

1. rate(metric_name[5m])
2. increase(metric_name[5m])
3. delta(metric_name[5m])
4. changes(metric_name[5m])

Answer:
A - is the correct answer. The rate function calculates the per-second rate of increase of a counter or gauge over a specified time range
B - is incorrect answer. The increase function calculates the absolute increase of a counter or gauge over a specified time range
C - is incorrect answer. The delta function calculates the difference between the current and previous value of a counter or gauge
D - is incorrect answer. The changes function counts the number of value changes of a gauge or counter over a specified time range