I am having problems with these kind of questions. Can anyone explain to me why the answer is D and not A.
Thanks.

Columnist: A democratic society cannot exist unless its citizens have established strong bonds of mutual trust. Such bonds are formed and strengthened only by participation in civic organizations, political parties, and other groups outside the family. It is obvious then that widespread reliance on movies and electronic media for entertainment has an inherently corrosive effect on democracy.
Which one of the following is an assumption on which the columnist’s argument depends?
(A) Anyone who relies on movies and electronic media for entertainment is unable to form a strong bond of mutual trust with a citizen.
(B) Civic organizations cannot usefully advance their goals by using electronic media.
(C) Newspapers and other forms of print media strengthen, rather than weaken, democratic institutions.
(D) Relying on movies and electronic media for entertainment generally makes people less likely to participate in groups outside their families.
(E) People who rely on movies and electronic media for entertainment are generally closer to their families than are those who do not.