______ of the rainbow were vivid  against the bright blue sky.

Hues are colors, the main feature of rainbows, which would look vivid, not dark (E) against the bright blue sky. Textures (consistencies) are not clear (A) in rainbows like colors are. Alabaster (C) is a pearly white color not seen in rainbows. Rainbows' colors appear in curved lines, but these are not dark (D); moreover, "line" (D) grammatically disagrees with the plural verb "were."