PCA (Prometheus Certified Associate) sample exam question with answer 434

Question:
Which of the following tools is represented by the description below?
We aim for our service to maintain at least 99.9% availability on a 28 day rolling window.

1. SLI
2. SLO
3. SLA
4. Error Budget

Answer:
B - is the correct answer
A - is incorrect as the given description implies a goal which is included in an SLO, not an SLI
C - is incorrect as an SLA requires an agreement between parties and the given description makes no reference to an agreement or consequences for not meeting the objective
D - is incorrect as an error budget describes how much time a system can be down without violating an SLO or SLA. For the given SLO description, the corresponding error budget is approximately 40 minutes