Which control lets you select manual pressurization?

The control that allows for selecting manual pressurization in the A320 is the MODE SEL switch. This switch is used to select the desired pressurization mode for the aircraft's cabin. In automatic mode, the system controls pressurization automatically based on aircraft altitude and systems configuration. By selecting the manual pressurization mode using the MODE SEL switch, pilots take direct control over cabin pressure, allowing for adjustments as necessary during different phases of flight or in response to system malfunctions.

Understanding this functionality is critical for managing cabin pressure effectively, particularly during scenarios such as rapid climb or descent, when the automatic system may not respond optimally. This allows pilots to ensure passenger safety and comfort by creating the desired environment within the cabin.

The other options, while relevant to various aircraft systems, do not pertain directly to the selection of manual pressurization.