PCA (Prometheus Certified Associate) sample exam question with answer 340

Question:
The metric node_fan_speed_rpm tracks the current fan speeds. The location label specifies where on the server the fan is located. Which query will return the fan speeds for all fans except the rear fan

1. node_fan_speed_rpm{location!~"rear"}
2. node_fan_speed_rpm{location!="rear"}
3. node_fan_speed_rpm
4. node_fan_speed_rpm{location~="rear"}

Answer:
B - correct answer