An authors use of situational irony builds a foundation of events that lead up to a stark conclusion. Murakami is an excellent example of this, given that through his novels he writes his characters into situations that are clearly antithetical to whatever has been occurring to said character. This can establish a frame of reference for the reader to assume the finale will go the same way, subverting expectations and providing a surprise. classic mystery trope.
I believe the best answer here is A. it uses imperfect coordinating structure.
King delivered his speech at the march on Washington for jobs and freedom on august 28,1963
The correct answer is B. The river deposited debris at every turn. There is a verb, a subject and an object, so it is considered a full sentence.