Which of the following statements is true regarding oxygen indicators?

Correct Answer: Option B — Prolonged exposure to gases such as CO2 may affect the accuracy of the indicator.

Electrochemical oxygen sensors can be poisoned or experience drift when exposed to high concentrations of carbon dioxide or other acidic gases over extended periods. This interference alters the chemical reaction within the sensor, leading to inaccurate readings. Regular calibration and bump testing are required to ensure sensor reliability before entry.