Which statement about portable radios is true?

The statement regarding portable radios having a range of approximately one mile is grounded in the operational limitations typically associated with these devices. Portable radios are designed for effective communication within a certain distance, which often falls around one mile in urban environments due to obstacles like buildings, terrain, and interference. This range may vary depending on the environment and the conditions under which the radios are operated, but stating a general range of one mile provides a clear understanding of their functional capabilities.

Additionally, portable radios are built to transmit with lower power than fixed radios, usually between 1 to 5 watts on average, which contributes to this limited range. Hence, this option appropriately reflects the practical use and expectation of portable radios in firefighting and emergency response scenarios, emphasizing their intended communicative function within a manageable distance.