Step 1: Story reference.
This is from Anton Chekhov's short story *The Bet*. The banker recalls giving the party 25 years ago when the bet was made with the young lawyer.
Step 2: Checking options.
(A) 15: Incorrect.
(B) 16: Incorrect.
(C) 20: Incorrect.
(D) 25: Correct.
Step 3: Conclusion.
Correct answer is (D) 25.
“One of these days you’re going to talk yourself into a load of trouble,” her father said aggressively. What do you learn about Sophie’s father from these lines? (Going Places)