What does the presence of stratus clouds generally indicate about air stability?

The presence of stratus clouds typically indicates that the air is generally stable with minimal upward movement. Stratus clouds are formed in stable air conditions where there is little vertical mixing. They often cover large areas and can create consistent grey overcast skies, usually associated with light precipitation or mist. Because of the stability of the air, significant turbulence and vertical air movement are reduced, making flying conditions typically calmer compared to conditions associated with more unstable cloud types, such as cumulonimbus clouds. Thus, this characteristic of stratus clouds makes option B the correct choice, as it accurately reflects the stable nature of the air when these clouds are present.