Explanation: The squelch control sets a threshold for the received signal strength. Its primary function is to mute the receiver when no signal (or only noise) is present, preventing constant static. Setting the squelch control to the "end of its range" such that no noise is heard means the squelch threshold is set very high, or fully "closed." In this state, the receiver will only unmute and pass audio for very strong signals that exceed this high threshold. Weaker signals, even if they are legitimate transmissions, will not be strong enough to "break" the squelch and will remain unheard. This condition effectively makes the receiver less responsive to faint signals, meaning its ability to pick up distant or low-power stations is significantly reduced. Therefore, setting the squelch to its maximum tightest setting results in minimum sensitivity. Options A is a consequence of reduced sensitivity, while C and D are incorrect as squelch directly impacts which signals are heard.