Emphatic stress is the placement of greater stress on a particular word or phrase in a sentence or expression in order to highlight its importance, contrast or to express a strong feeling or affirmation. This stress changes the meaning of the sentence or draws attention to the information emphasised. In emphatic stress questions, the goal is to find the question that the expression is trying to correct. The word in capital letters is stressed to correct a mistake made in the question. Therefore, the option that has a word different from the one in capital letters should be the correct answer.

In the sentence, "They FLEW to Abuja," the question that best fits is "Did they go to Abuja by road?" 

It shows that the responder to the question is trying to correct the fact that they did not go by road but FLEW to Abuja.