I believe the answer is, actually, D. The red will be too exciting and distracting to the calm library.
If you research the library, it is actually quite a colourful place, but the red on the inside, as well as the outside, would have been too much and indeed; distracting and exciting.
The second image, titled, “Nautilus, 1927” illustrates how a lack of texture enhances the illusion of an objects smooth surface on the two-dimensional print. Using rather flat lighting enhances the affect by filling in any local texture. This reduces contrast changes even more.
That's a realistic sculpture<span />