The title of which, which title

Hi!

A book says only the first sentence is acceptable. I don't know why the second sentence is not acceptable.

The movie The Wizard of Oz, _________ is taken from the book of the same name, has been a children's favorite for years.

a) the title of which
b) which title

Thanks for your help.

Tom

I have to admit I don't either, except that b) is a little more formal and fussier-sounding--but maybe I'm missing some fine point of grammar.

Oh, I think I see--the subject of the sentence is the word "movie", not "The Wizard of Oz"; and "movie" isn't a title. That's why.