The correct answer is option A ("What I will do if he decides to go down, I don't know. What I'll do if he sounds and dies I don't know. But I'll do something. There are plenty of things I can do").
We refer to journalistic style in writing as the use of certain devices, structures and resources that are most commonnly associated with news articles, chronicles and similar kinds of pieces. They can be easily identified for the use of short sentences and paragraphs that have a very straight-forward feel to them. The message often feels urgent and we get the sense that the author is trying to quickly make their point.
Example "A" presents many of these features while none of the others are brief or to-the-point at all.
Hope this helps!