Respuesta :
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.
Seeing is believing is an example of the theme in this excerpt. The scientist needed to send the time-traveling device through time in order to prove to the character that it was real, rather than just informing him about what it could do. Hence, option C is correct.
What is the concept of the story?
The speaker, a psychologist, and potentially more individuals are shown how a time traveller uses his machine to go back and forth in time.
When the time traveller touches a lever to indicate that it is presumably travelling into the future, the machine then vanishes. Since time travel is the fundamental premise of the tale, it is what is being discussed in the extract.
As a result, the primary subject of this passage is time travel, specifically how a time traveller possesses a machine that can travel across time.
Thus, option C is correct.
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