Critical Reasoning

Despite the fact that many professional writers consider travel writing a lesser form of journalism, it is in fact a legitimate journalistic enterprise, since it employs classical journalism techniques such as detailed research into the history of a given locale and extensive interviews with local residents.

The argument above depends on which one of the following assumptions?
(A) If a literary work is crafted via extensive interviews of noteworthy subjects it should be viewed as legitimate.
(B) Since travel writing follows the methods of traditional journalism, it will produce intriguing material for readers.
(C) Any writing that does not employ classical techniques is a lesser form of journalism.
(D) If a literary pursuit involves classical journalism techniques, then it should be considered a legitimate journalistic enterprise.
(E) The interview process used by travel writers can provide further information about the history of a region

OA: D

What's the best approach to determine the answer? Any experts help?