A. $1,000,000 would still make this only the second largest prize in the field.
Still it's the second largest prize - But that doesn't mean the probability of applications will remain the same.
Let's say you didn't apply before because you thought 500k was not worth it, but now 1 million seems worth to find the solution. So, you may apply because of the
increase in the amount of the prize.
Another e.g. previously the amount for the first prize was $1.2 million. So, people were applying for $1.2 million application instead of $500k. But now, the prize (1 million) is closer to 1.2 million. So, there is a chance of increase in the successful applications.
B. At $500,000, the prize did not, in fact, attract a single application.
Doesn't mean this time no application will come.
C. The doubling of the reward would merely attract more, and more sophisticated, bogus applications than the grant already attracts.
Because conclusion talks about
successful applications. So, though the prize money is doubled but there will be no successful application, so the situation remains the same. So, let's keep this.
D. Most of the best-qualified researchers in this field are already well-funded and paid.
But someone may want to earn more, so that person may still apply. The definition of
well-funded vary from person to person.
E. Years ago, researchers discovered physical barriers to the specified application that no one has been able to overcome.That was years ago. The very aim of the research is to find that solution, i.e., how to overcome those barriers. The previous prize wasn't able to attract the successful applications. But the increase in the prize may attract someone to find the solution of this problem.
So, I will go with C. Please share your thoughts.