Answer:
"A flow of disappointment rushed across my mind and for a moment I felt that I had built the Time Machine in vain."
Explanation:
Out of all the options/phrases, this sentence clearly expresses the feeling that the time traveler was surprised and disappointed by the beings' lack of understanding. In the passage, the Time Traveler makes a reference to thinking that the beings would be far advanced, so he is disappointed that that is not true, as they don't understand where the Time Traveler has come from, and they think he has come from a thunderstorm.
