The correct answer is C: Tunes through a range of frequencies to check for activity. The scanning function of an FM transceiver tunes through a range of frequencies (or memory channels) to check for activity. When it detects a signal (opens squelch), it stops so you can listen. Scanning is a useful feature for finding active frequencies. The transceiver automatically tunes through a preset range of frequencies or through memory channels, stopping when it detects a signal. This allows you to monitor multiple frequencies without manually tuning. You can typically set scan limits, choose which memory channels to scan, and adjust how long the scanner pauses on active frequencies. This is a standard feature on most modern FM transceivers.