【正确答案】 C

【答案解析】Idiom; Logical predication
The sentence's use of the form a direct link from X to Y is unidiomatic; the correct idiom would be of the form a direct link between X and Y. Because of the inappropriate use of from, the sentence initially sets up the expectation that the claim the sociologists make is that they became aware of a direct link from the appearance of news stories about violence.
A The sentence uses the unidiomatic form a direct link from X to Y.
B The sentence uses the unidiomatic form a direct link between X to Y.
C Correct. The sentence uses the correct idiomatic form direct link between X andY.
D The sentence uses the unidiomatic form a direct link with X to Y.
E The sentence uses the unidiomatic form a direct link with X and Y.
The correct answer is C.