What was a major issue with earlier passive RF devices?

The option indicating that earlier passive RF devices had limitations in receiving transmissions in certain areas of the home is correct because it highlights a significant technological limitation of those devices. Passive RF devices often relied on establishing a clear signal path to a central receiver without actively boosting or altering the signal. This design made them susceptible to interference from physical obstructions like walls or furniture, which could impede the transmission of signals, resulting in inadequate coverage in some areas of a household.

As a result, users could experience gaps in monitoring zones, leading to potential issues in tracking compliance and ensuring safety, particularly in domestic settings. This was a critical drawback that prompted advancements in technology, which aimed to enhance the range and reliability of RF tracking systems used in probation and parole practices.

The other options do highlight challenges that may have been associated with RF devices, such as maintenance costs, battery life, and comfort, but the core issue of transmission gaps in certain locations directly speaks to the operational limitations that impacted monitoring accuracy and reliability, making it a major concern in earlier implementations of these technologies.