PCA (Prometheus Certified Associate) sample exam question with answer 370

Question:
Which of the following queries contains a logical binary operator?

1. up{job="node"} == 0
2. up{job="node", instance="node1"} + up{job="node", instance="node2"}
3. up{job="node", instance="node1"} or up{job="node", instance="node2"}
4. up{job="node", instance="node1"}[10m]

Answer:
C - is the correct answer. More at Logical/set binary operators
A, B, D - is incorrect as this query does not contain a logical binary operator (and, or or unless)