The argument is that “political journalists are not doing job properly”.
A – Wrong
The text does not suggest that the journalists are doing it deliberately. So we cannot say that it is an assumption.
B – Wrong
Nothing written in the text suggests that voters believe everything they see in the newspapers.
C – Correct
The text says that journalists are not doing their job properly because they include all details of the minister’s incompetence and omit any alternative views. However, the text assumes what the job of political journalists is. It assumes that it is the job of the journalists to inform the voters.
D – Wrong
This is neither true nor an assumption
E – Wrong
The text does not assume that journalists aim to destroy the careers of politicians. It just highlights that journalists tend to focus on the incompetence of the minister.