This question asks you to decide where a sentence could be added to one of the paragraphs. To answer this question, you should study the sentence to be inserted and then look at the context before and afted each insertion box. The sentence mentions this expression about the king, and the context before insertion box 2D mentions the kine and the expression checkmate. From this, it can be determined that the sentence should be added at insertion box 2D. You should click on 2D to answer this question.