Which control allows the user to adjust the stability of an oscilloscope display?

The trigger control is essential for stabilizing the display of an oscilloscope because it determines when the oscilloscope captures and displays the waveform. When a specific voltage level is reached, the trigger generates a signal that tells the oscilloscope to start displaying the waveform from that point. This allows subsequent sweeps of the oscilloscope to align with that initial point, resulting in a stable and consistent waveform on the display. Without proper triggering, the waveform may appear to drift or be unstable, making it difficult to analyze accurately.

Other controls like gain control and time division control serve different purposes. Gain control adjusts the amplitude of the signal displayed, while time division control changes the time scale of the display, affecting how much of the waveform is visible over a particular time span. However, neither of these can directly stabilize the waveform display, which highlights the critical role of the trigger control in oscilloscope operation.