What term describes the composition of a group of pencils originating from all of the points on a light source?

The correct term that describes the composition of a group of pencils originating from all the points on a light source is a beam of light. When discussing light sources, a beam of light refers to a coherent stream of photons that can be thought of as a collection of light rays or pencils of light emanating in a certain direction.

In optics, a beam is often visualized as a collection of individual paths or rays originating from a single source. This concept helps in understanding how light propagates through space and interacts with various optical elements.

The term “light cone” describes a geometric representation used in physics and can represent the range of light signals that can be observed from a point, but it doesn't specifically relate to the collection of rays or pencils originating from a light source.

The optical spectrum refers to the range of wavelengths that make up light but does not denote the physical arrangement or movement of those light rays from a source. A pencil of light is more typically used to refer to an individual ray or beam of light and does not encapsulate the entire collection of rays.

Thus, a beam of light encompasses the idea of multiple rays originating from a light source and traveling outward, aligning with the essence of the question regarding the composition of those rays.