In the early twentieth century, an extraordinary painter could influence nearly all advanced artists, but today, for any one artist to influence practitioners of genres as varied as painting, video, and photography is nearly impossible.
(A) as varied as
(B) as varied as are
(C) as varied as those of
(D) that are as varied as
(E) that are as varied as are
(B) This question revolves around a meaning issue. In this answer choice, it's painting, video, and photography that are varied. But that's the wrong meaning. The variation is simply in the genres themselves; painting, video, and photography are quite varied genres. How do we know this? The idea is that a painter could once influence all advanced artists, because all art was so similar. But now, video and photography are so different from painting, it's unlikely a painter could influence someone working in those media.
(C) "Those" could only refer to "genres," which makes no sense: "...practitioners of genres as varied as the genres of painting, video, and photography." At best, this is redundant. At worst, it's crazy wrong, because there aren't genres
inside the genres!
(D) + (E) These both carry the meaning that the genres being listed have the variety inside of them (just as (A) did).
Let me know if that makes sense, or if you have follow-up questions.
-t