In which mode does the pitch reference change by 1/2 degree with each click of the VS wheel?

The pitch reference changes by 1/2 degree with each click of the VS (Vertical Speed) wheel in the pitch mode. This mode allows pilots to make fine adjustments to the aircraft's pitch attitude, facilitating tactical control over the rate of climb or descent. When the pilot uses the VS wheel in this mode, they can precisely set the vertical speed target, enabling them to manage aircraft performance more effectively.

In contrast, other modes such as climb and level do not utilize the VS wheel in the same manner to adjust pitch reference. The climb mode predominantly focuses on achieving a specific rate of climb without the incremental adjustments that pitch mode allows. Level mode also does not involve direct manipulation of pitch attitudes using the VS wheel but instead maintains a constant altitude. Therefore, pitch mode is distinct in its functionality, making it the correct answer regarding the adjustment of pitch reference with each interaction with the VS wheel.