1 In this sense it is nearly synonymous with synopsis. ( 2 n.) The tracing of things to their source, and the resolving of knowledge into its original principles. ( 3 n.) A syllabus, or table of the principal heads of a discourse, disposed in their natural order.
A lightning rod or lightning conductor is a iron rod that is used to make lightning strike it, rather than strike something else. It is part of a lightning protection system. Such a system is made of many such rods. These rods are usually placed at high points of buildings and structures.
Rods and cones are photoreceptors that are located in the retina of the eye. Rods are responsible for vision at low light levels while cones are responsible for vision at higher light levels. Therefore, rods are very sensitive to light. Rods work well at night when light is low. Cones, however, are responsible for color vision and high visual spatial acuity. Therefore, rods cannot distinguish colors. With these differences, the correct answer is: A. Rods are very sensitive to light but do not distinguish colors.