A leading critic of space exploration contends that it would be wrong, given current technology, to send a group of e...

shunhe on April 3, 2020

Hi @NateT,

Thanks for the question! Let’s take a careful look at what the argument is saying. In the final sentence of the stimulus, the author writes that a final catastrophe is quite unlikely at any given stage if such a backup system is in place, and earlier, the author mentions that the critic of space exploration exaggerates the risk of fatal catastrophe. Now, (D) tells us that the flaw in the passage is that the author infers that something will work (for sure) merely because it could work. And yes, the “something” and “it” refer to the backup system, as you mentioned. But the claim in (D) is not what the author is claiming. The author is not claiming that the safety system will definitely work; the argument merely claims that the risk is exaggerated, and that the backup system mitigates it to a significant extent. Because the argument is not making an argument based on certainty, but rather based on probability, (D) must be incorrect. The correct answer choice, (A), has to do with the fact that the safety of the crew is true of a whole (the trip to Mars) based on each individual part (the stages of the trip to which the argument refers). This is different from what (D) says.

Hope this helps! Feel free to ask any other questions that you might have.