Answer: yaka material culture ( craving , basketry, metalwork, and weaving) is well known. Yaka masks and figures have distinctive bulky forms , globular eyes, and turning up noses some are polychrome and many have raffia clothes or fringes attached. Yaka style dominates the expressive forms of neighbouring groups.
According to wiki,”a tone is produced either by mixing a color with grey, or by both tinting and shading” so it’d probably be d but honestly cannot tell if that’s supposed to grey or blue
