单选题 In several nineteenth-century paintings the marble buildings of the Acropolis in Athens are portrayed as being reddish, but the buildings do not now appear reddish. The marble's natural color cannot have changed since the nineteenth century, so the paintings must not be showing the color of the buildings as they actually appeared.
Which of the following, if true, most seriously undermines the argument above?

【正确答案】 B
【答案解析】