What report would indicate a cloud layer located 200 feet below station elevation?

In aviation weather reporting, the notation indicating the presence of clouds is significant for flight planning and safety. When interpreting the question, it is important to understand that a cloud layer reported as being below the station elevation does not align with typical reporting formats.

The choice that represents the absence of any cloud layers, especially one that is below station elevation, is denoted by three forward slashes (///). This indicates that there is no cloud data available, which can imply that cloud layers are beyond the reporting capabilities or considerations for the given station.

In this context, the presence of clouds is not recorded because a layer at 200 feet beneath the station elevation indicates a lack of data relevant to traditional reporting mechanisms. Therefore, the use of three slashes is the accepted method of indicating that such observations do not exist or are not reported, particularly when they fall within operational constraints or range of visibility.

Other options like -200 or M200 do not accurately communicate the scenario described in the question, and "Not reported" does not follow the specific formatting used in aviation weather reports. The correct choice captures the essence of the situation accurately by indicating a complete absence of reported cloud layers in that specific range.