The shadows of a building at noon are:

The correct option is C Black and short
Shadows are the dark patch formed by an opaque object. It is formed when the light from a source is obstructed by an opaque object. The size of the shadow does not give the idea of the exact size of the object because it keeps changing.
It changes with the relative position of the object, source of light and screen on which the shadow is formed.
The shadow always forms on the opposite side of the source of light. The position of the sun affects the size of the shadow. Our shadow is shortest at noon. The length of our shadow goes on decreasing till noon. The length of our shadow starts increasing in the afternoon. And our shadow becomes very long in the evening and just before sunset. As the sun rises in the sky, the shadow of a building shortens.
Hence, shadow of the building at the noon is black in colour and shortest in size.