When must the station and its records be available for FCC inspection?

The correct response indicates that a station and its records must be made available for inspection at any time upon request by an FCC representative. This aligns with the regulations and guidelines set forth by the FCC, which emphasize the importance of compliance and transparency in radio service operations.

The requirement for immediate availability reflects the FCC's role in monitoring and regulating the airwaves, ensuring that operators adhere to rules concerning licensing, interference, equipment standards, and operation protocols. By allowing representatives to perform inspections at any time, the FCC is able to enforce regulations effectively and maintain the integrity of communication services.

In context, other options suggest conditions under which inspections may occur that do not fully encompass the FCC's authority. For example, indicating a specific time frame like ten days or requiring prior written notification would limit the FCC's ability to act swiftly in cases of apparent violations or concerns. Similarly, requiring a valid warrant may not align with the standard legal framework that grants the FCC the necessary oversight without that additional legal hurdle.