Ceiling is defined as:

Ceiling is defined as:

• A. The height above the earth's surface of the lowest layer of clouds or obscuring phenomena reported as broken, overcast, or obscuration, and not classified as thin or partial.
• B. The highest cloud layer.
• C. The distance from the runway to cloud base.
• D. The visibility at ground level.

Answer: (A)

Ceiling is the vertical measure of how high the lowest cloud layer that is significant to flight sits above the earth’s surface. It specifically refers to the base of the lowest layer that is reported as broken, overcast, or obscuration, and it’s not classified as thin or partial. This definition matters because it tells you how much of the sky is actually preventing a clear vertical view, which affects whether you can fly VFR or must operate under IFR. The other ideas don’t fit: the ceiling is not the height of the highest cloud layer, so that option describes something different. It isn’t the distance from the runway to cloud base, which isn’t a standard aviation measure. And it isn’t ground visibility, which measures horizontal sight distance at the surface, not the vertical extent of cloud cover.

Ceiling is the vertical measure of how high the lowest cloud layer that is significant to flight sits above the earth’s surface. It specifically refers to the base of the lowest layer that is reported as broken, overcast, or obscuration, and it’s not classified as thin or partial. This definition matters because it tells you how much of the sky is actually preventing a clear vertical view, which affects whether you can fly VFR or must operate under IFR.

The other ideas don’t fit: the ceiling is not the height of the highest cloud layer, so that option describes something different. It isn’t the distance from the runway to cloud base, which isn’t a standard aviation measure. And it isn’t ground visibility, which measures horizontal sight distance at the surface, not the vertical extent of cloud cover.