Pigments are always made of natural materials

It seems that you have missed the necessary options for us to answer this question so I had to look for it. Anyway, the answer to the given statement is FALSE. Pigments are NOT always made of natural materials. Pigments can either be man-made or the one that occurred naturally as what you see in our environment. Hope this helps.

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.

It should be d if not then c