In research discussed in class and in the book, most of the participants who viewed a videotape of people tossing a basketball back-and-forth remained unaware of an umbrella-toting woman (or, in another study, a gorilla) walking across the screen. This illustrated: A. perceptual constancy (especially color constancy). B. selective attention and inattentional blindness. C. difference thresholds. D. signal detection,