题目选项分析

Art experts have attributed the enduring intrigue of Leonardo da Vinci's Mona Lisa to everything from her enigmatic smile, for which there has never been an explanation, to her association with the rich and powerful families of Europe.

Art experts have attributed the enduring intrigue of Leonardo da Vinci's Mona Lisa to everything from her enigmatic smile, which has never been explained, to her association with the rich and powerful families of Europe.