The correct option is D 4 only
Shadows are the dark patch formed by an opaque object. It is formed when an object blocks the path of the light. If an opaque object comes in the path of light , stop the light rays from traveling through it. This creates an area of darkness behind the object.
For the formation of shadow there must be a source of light , an opaque object to obstruct the path of light and a screen to catch the shadow.
No shadow can be formed without the light source, opaque objects and a screen.
Hence, these are the essential conditions for the formation of shadows.