What is the minimum distance for placing detectors from any potential openings to the outdoors?

The correct choice emphasizes the importance of placing radon detectors at a minimum distance from potential openings to the outdoors, which can influence the accuracy of radon measurements. The recommended minimum distance of 3 feet is based on guidelines that aim to avoid interference from outdoor air, such as drafts or variations in weather, which might skew the radon levels detected indoors.

By ensuring that detectors are situated at least 3 feet away from doors and windows, the risk of erroneous readings due to outside air infiltration is mitigated. This practice ensures that the measurements reflect the radon concentrations more accurately within the indoor environment, providing reliable data for assessing radon exposure in homes or buildings.