Which of the following controls could be used if the voice pitch of a single-sideband signal seems too high or low?

Using the receiver RIT (Receiver Incremental Tuning) or clarifier is the correct approach for adjusting the voice pitch of a single-sideband (SSB) signal that may seem too high or low.

When receiving SSB signals, the pitch can vary depending on how the transmitter is tuned and may not always be exactly on frequency due to fluctuations or signal drift. The RIT or clarifier allows the operator to make fine adjustments to the frequency without changing the overall tuning of the receiver. This can help in bringing the audio quality of the voice back to a more natural sound, thereby correcting any pitch discrepancies caused by the original transmission frequency.

The other controls mentioned do not serve this specific function. For example, AGC (Automatic Gain Control) or limiter primarily affects the audio level rather than tuning precision. Bandwidth selection adjusts the range of frequencies that the receiver processes, which can influence audio clarity but not pitch directly. Tone squelch is used to filter out unwanted signals based on audio frequency characteristics, but it does not offer the precision tuning needed to correct the pitch of the received SSB signal.