Which sentence from the story "The Ransom of Red Chief" demonstrates irony only after reading the story's conclusion? A. "There was a town down there, as flat as a flannel-cake, and called Summit, of course." B. "Bill and me had a joint capital of about six hundred dollars, and we needed just two thousand dollars more to pull off a fraudulent town-lot scheme in Western Illinois with." C. "We selected for our victim the only child of a prominent citizen named Ebenezer Dorset." D. "Bill and me figured that Ebenezer would melt down for a ransom of two thousand dollars to a cent."

D. "Bill and me figured that Ebenezer would melt down for a ransom of two thousand dollars to a cent."

Explanation:

In O. Henry's short story "The Ransom of Red Chief", Bill and Sam decide to kidnap the son of "an important citizen", Ebenezer Dorset, in order to gain $2000 needed for their fraudulent affairs.

But, their plan soon falls to pieces when they discover that they just can't handle the boy who is having fun with the kidnappers and keeps playing pranks on them.

Unable to control the boy's behaviour, Bill and Sam, lower the ransom, hoping that they will get rid of the boy sooner that way.

However, familiar with his son's character, restlessness and all the mischiefs he's capable of, Ebenezer makes a counterproposal to the kidnappers; he'll take the kid back if they pay him $250 for that.

This is the best example of irony in this story, since the kidnappers didn't get what they hoped for and even ended up losing some of their money.