Explanation: P25 (Project 25) is a digital radio communication standard. Unlike analog signals, where audio directly modulates the carrier wave, P25 systems encode voice into a digital data stream. A conventional analog scanner can tune to the frequency of a P25 system, but without the appropriate digital signal processing (DSP) hardware and software, it will only produce an unintelligible noise or "digital hash." To monitor a P25 system and hear the actual voice communications, a scanner must have built-in P25 decoding capabilities. This allows the scanner to receive the digital bitstream, process it, and convert it back into audible speech. Therefore, option C is correct. Option A is incorrect because a scanner without P25 decoding cannot convert the digital signal into voice. Option B is incorrect because scanners *can* monitor P25 if equipped. Option D introduces "P26 decoding," which is not a relevant or existing standard for this context.