Which of the following could be a hazard affecting motion detector performance?

Motion detectors are sensitive devices that rely on detecting specific changes in their environment, typically through infrared heat emission from objects (such as people) moving within their field of view. Both extreme temperature variations and the presence of animals can adversely impact the performance of these detectors.

Extreme temperature variations can disrupt the ability of the detector to identify warm-bodied individuals against a background that is either too warm or too cold. For instance, if the ambient temperature is very high, the motion detector may struggle to distinguish between significant heat signatures (like those from people) and the heat generated by the environment, leading to false alarms or missed detections.

Similarly, the presence of animals can also interfere with motion detection. Animals can emit heat and move within the detectors’ range, resulting in either false positives or triggering the system when it isn't necessary. Motion detectors can often be set to different sensitivity levels, but if not properly calibrated, they may react to even small animals, complicating the security situation.

Acknowledging both points clarifies why answer choice indicating that both extreme temperature variations and the presence of animals are potential hazards affecting motion detector performance is correct.