B for me.
But first, the conclusion can be identified as - "Media has become a powerful tool of manipulating people’s minds and shaping opinions"
A: the first describes a phenomenon supporting the author’s main conclusion; the second is this conclusion
> WRONG. The second bolded part does not state the conclusion.
B: the first is an example cited in support of a certain position; the second is a relevant addition to this position
> CORRECT. The first bolded part is an example. The second bolded part adds information to the author's position that is stated in the conclusion
C: the first describes a phenomenon illustrating the author’s main point; the second is offered as an explanation of this phenomenon
> WRONG. The second bolded part talks about how people form opinions based on what they learn from the media, and it does not provide an explanation of the phenomenon.
D: the first states the author’s main idea while the second develops this idea
> WRONG. The first bolded part gives an example. It is the conclusion that states the author's main idea.
E: the first is a fact counting against the argument’s main conclusion; the second is the evidence supporting this conclusion
> WRONG. The first bolded part is a fact alright, but it supports the argument's main conclusion, and does not contradict it.