It was only after Katharine Graham became publisher of The Washington Post in 1963 that it moved into the first rank of American newspapers, and it was under her command that the paper won high praise for its unrelenting reporting of the Watergate scandal.
A) It was only after Katharine Graham became publisher of The Washington Post in 1963 that it moved into the first rank of American newspapers, and it was under her command that the paper won high praise
B) It was only after Katharine Graham's becoming publisher of The Washington Post in 1963 that it moved into the first rank of American newspapers, and under her command it had won high praise
C) Katharine Graham became publisher of The Washington Post in 1963 and only after that did it move into the first rank of American newspapers, having won high praise under her command
D) Moving into the first rank of American newspapers only after Katharine Graham became its publisher in 1963, The Washington Post, winning high praise under her command
E) Moving into the first rank of American newspapers only after Katharine Grahame's becoming its publisher in 1963, The Washington Post won high praise under her command
This question is posted earlier, however, the explanation provided is not that I can understand. My particular question is, we have 3 "It" in original sentence. First one I think is not referring to anything, second one is referring to WP (however it can refer to KG or publisher as well) and the third one again has no referent.
In earlier explanation, it said in C it is not clear what It is referring to, on the same line I think A is even more ambiguous. Can you please explain how in C It is ambiguous and in A it is not?