Which of the following gases could cause cross interference on a carbon monoxide sensor?

A carbon monoxide sensor is designed to detect the presence of carbon monoxide (CO) specifically. However, certain gases can interfere with the sensor's accuracy and lead to false readings. In this case, hydrogen sulfide is known to cause cross interference on carbon monoxide sensors because it can chemically react with the sensor’s detection method, often resulting in misleading higher readings of carbon monoxide.

When hydrogen sulfide is present, it can mimic or interfere with the detection mechanism used by the sensor, causing a reaction that impacts the sensor's performance. This is particularly important in environments where multiple gases may be present, as accurate detection of carbon monoxide is critical for safety.

In contrast, the other gases listed, such as carbon dioxide, nitrous oxide, and ozone, do not have the same significant cross-interference effect on carbon monoxide sensors, making hydrogen sulfide the most relevant choice in this context.