单选题 This selection is primarily concerned with ______.

A、 the eye's adaptation to color
B、 the properties of colored surfaces
C、 the color of colors
D、 the effect of changes in color intensity

【正确答案】 A

【答案解析】可在本段主题句“Both of these effects seem to be due in large part to the mechanism of color adaptation mentioned earlier.”中找到答案。A眼睛对色彩的适应性；B道具表面颜色；C色彩本身；D颜色突然转换的影响。