he agrees with nadia the author is saying that the ban will not help obesity and will not work .
The detail that best reveals that Mr. Rainsford opposes Zaroff's idea of the ideal prey is Mr. Rainsford's response near the end of the passage when he states that he is a hunter, not a murderer. This statement shows the reader that Mr. Rainsford believes that Zaroff hunting humans as prey makes him a murderer.
The answer is effective because the president outlines the emotional reasons for entering war. Hope this helps.