I would say that within the context of the article, choice 2 would be correct. [....] leading me to believe that the movements derived their focus from literary fiction.

If the movements derived their focus from literary fiction(LF), they manifested themselves after the works of fiction did, so how could LF shift focus to these movements (which is what choice 2 says) when in fact they were not there before the LF was written? (There is the possibility that there could have existed a few books of this genre without considering LFs focus shifted. Either that or we blame the relativeness of time .)

Actually, I think you maybe just mixed (a) and (b) up? At least your reasoning sounds to me like you were going for (a), correct me if I'm wrong.