[Solved] Fred systematically observes how changes in lighting affect his rat's lever-pressing behavior. Which research design best characterizes Fred's investigation? A) cross-lagged panel design B) single-case experimental design C) nonequivalent groups design D) correlational design Seven Components: Typically refers to the essential elements or parts that make up a whole; context needed for a specific definition. Visible Fibers: Fibrous materials or threads that can be seen with the naked eye, often referring to those found in textiles, paper, or other composite materials. Invisible Fibers: Microscopic or very fine fibers that are not visible to the naked eye, which can be natural or synthetic and have various applications, including in textiles and forensic science. Black (UV) Light: Ultraviolet light that is not visible to the human eye but can cause fluorescent materials to glow, often used for amusement or inspection.