What type of card may be seized if a station is suspended?

The correct answer is the signature card because this type of card is directly associated with a registered inspection station's authorization to conduct vehicle inspections. If a station's license or permit is suspended, the signature card, which often grants authority to perform inspections and certifies that the station meets the necessary standards, needs to be seized. This action ensures that no inspections are conducted at that location during the suspension period, maintaining the integrity of the inspection process.

Regarding the other options, employee identification cards pertain to individuals and their employment status, insurance cards relate to proof of vehicle insurance, and membership cards do not have a direct connection to the operational authority of an inspection station. Thus, these cards do not hold the same importance in terms of the inspection process and do not require seizure if a station is suspended.