Is it possible for wave action to occur in dry air conditions?

Wave action can indeed occur in dry air conditions, which is why the chosen answer is correct. In the atmosphere, wave phenomena, such as gravity waves or Kelvin-Helmholtz instability, can be generated by various factors, including wind shear or topographical influences, even if no moisture or clouds are present. These waves are a result of disturbances in the vertical motion of air, which can be influenced by temperature gradients, pressure changes, or terrain features.

Clouds are not a prerequisite for wave action, as the physical processes that create these atmospheric waves can occur independently of moisture. In fact, many observational studies have documented wave activity in entirely clear air, highlighting that the dynamics of the atmosphere can be complex and operate under a variety of conditions.

Other options suggesting conditions such as needing clouds or being unlikely overlook the fundamental atmospheric science principles that allow waves to form due to density and pressure variations in the air, regardless of moisture content.