The question that is being raised here is this one: "Which of the four sentences is neutral?"
Here are the choices. A. 4 <span>B. 2 </span> <span>C. 1 </span> <span>D. 3 </span> The correct answer is this one: "B. 2" <span>Netta and Jim expressed different views on free trade.</span>
Your answer would be "seeing is believing." The scientist was only telling the character about what the time traveling machine could do, but needed to actually show the character that the machine wasn't a fraud by actually sending it through time.