To start off with why (E) is right, we should direct our attention to lines 36-39. We see here that Eileen Gray "often used modern materials, such as tubular steel, to create furniture...that, although visually austere, meet their occupants' needs." The chair has a simple form which fits the human form and is made out of metal, ticking all of our boxes: furniture, visually austere, using modern materials, meets occupants' needs.
(D) can be eliminated by lines 14-17, where the author discusses Gray's avoidance of "the flowing, leafy lines of the Art Nouveau movement," instead preferring the juxtaposition of straight lines and simple forms. A round, wooden picture frame with colorful shells and inlaid with various decorations does not fit Gray's motif. Hope this helps!